Heading west?

3 to 4 weeks

Look up average temperatures in the areas where you plan to stay. You may wish to "go higher" which is usually cooler.

When you look at distances, a good rule of thumb (and also easy math to do in your head) is an average of 50 mph. Not that you'll be driving that slowly, but once you figure in stops for fuel, food, bio, etc, it comes out to about 50 mph.

Next, figure out your personal preference for driving. How far do you like to drive in a day and how many days in a row do you feel like driving? This will determine how far you can get with your available time.

Another variable is what kind of camper are you? Do you like to stay in RV parks, state parks, COE, boondocking, etc.? Do you make reservations and stick to a schedule, or do you like to wing it?

My wife and I took an 11,000 mile trip year before last without any solid destinations or reservations. We never backtracked, which gave us three general compass points to choose from on any travel day (ruling out the direction we just came from). The night before a travel day, I would pin my wife down to a general direction and then I'd glance at the available places to stay in that area. Then the next day on the road around one or two in the afternoon I'd start to bug her to pick us a spot and call ahead to book it. I don't think we could get away with that during the current RV boom though.

And yes, this probably isn't the right place for this question. The Roads and Routes forum is really for directions and suggestions for getting to Point B from Point A. I'll move this to General RVing for you.

We went on a western jaunt from SC a few years ago. Spent a month. Not nearly enough time to have a relaxing trip. If you like driving 6-8 hours a day then perhaps you can do all you want in that timeframe.

How long it takes really depends on what you intend to do and how long you take to do that. I guess there are some practical hard minimums based on driving speeds and times, but even so what's a reasonable minimum length for such a trip varies a lot based on who's driving (and if you have more than one driver to share the duties).

Personally, I'd likely plan a minimum of five days each way between CT and one of those states, which leaves basically no time for doing anything along the way besides eating and sleeping. (Four days might barely be possible for me, depending on the final destination.) Anything much less than about three weeks would seem to me to not be worthwhile for the trip, assuming the goal is tourism/vacation; with less time, I'd opt to fly or take Amtrak out or something, or choose a destination closer to home.

You, of course, may cover more or less distance in a day comfortably than I do.

When you look at distances, a good rule of thumb (and also easy math to do in your head) is an average of 50 mph. Not that you'll be driving that slowly, but once you figure in stops for fuel, food, bio, etc, it comes out to about 50 mph.

X2. This rule of thumb works very well.

If you don't want to feel rushed and depending on where you go, 3-4 weeks is the minimum I'd plan. I've been out to SD, CO, WY & MT twice and it's a long drive to get out there. You will lose 3-5 days each way just driving, depending on where you go.

I'll also ditto the 50 mph rule.
Another big suggestion is to visit a FEW places and take you time at each. Newbies tend to want come up with a long list of places which means they spend most of their vacation driving from place to place.
We used to pick a central location and do day trips from there.
So decide how many days you have.
Plan ob 5-6 days each way for Utah. Eastern Colorado is a day less but you are more limited in parks, Rocky Mountains and Great Sand Dunes. I think RMNP may require tickets now. Better check on that.
Taking I80/90 west will run you thru the South Dakota Parks: Badlands and Rushmore with some other minor stops.
Utah: Zion and Arches are absolutely mobbed, packed, too many people. Zion has shuttle tickets you have to buy online. Arches lockes the gates when full, Zion will keep you waiting in a traffic jam for hours to get to a parking lot which will probably be full.
Capitol Reef has fewer people. Canyonlands also but you need at least a high clearance vehicle to drive the roads. Cedar Breaks is little visited but only open 3-4 months a year.
AZ: Many indian ruins parks but the are hotter than Hades in summer. So are Zion and Arches BTW.South Rim of the Grand Canyon also flooded with mobs. But cooler. North Rim has fewer people and is cooler yet.
Yellowstone is huge and has a lot of people. It is cooler, but expect in park traffic jam. Glacier seems to be getting mobs and requires difficult tp get tickets.
And lets not forget the big issue, where will you stay. Lodging/camping around the great parks needs to be reserved six months or more in advance.

We are going from coastal SC to Moab and are taking eight days to do it. Short days will give us time to relax or explore a bit locally. We will be spending a week in Moab and then a week in Cortez CO and then back with a few two and three day stays in places of interest to us. Total trip will be just over five weeks. We did the trip in three weeks when we were working and as beautiful as the trip was, it was physically exhausting and we were 16 years younger.

Going to be very difficult making reservations for every night with a trailer. 6-8+ weeks, especially if you only average 50mph and only drive 6-8 hours/day. It’s 2000 miles to RMNP so that’s 6 days of finding CGs and setting up each night even if it’s just putting a slide out and cooking. Are you really going to unhook the car and go exploring each night?

Even though we’ve been doing this for decades, our objective is still to get to CO (or WY) and then slow down. Left GA Monday evening (5 days ago) and made the mistake of not using the Interstates as much…trying something new that everyone raves about, the black roads. I’m surprised I still have a driver’s mirror (over width load on narrow road with no shoulder) and that the windshield didn’t pop out…narrow 2 lane roads and a closing speed of 125 mph with only 2-3’ of separation with the 18 wheelers.

Still made it past Denver (1500 miles) by Wednesday afternoon…we never stop before a big city as inbound traffic in the morning will be worse. Got into our 1st choice of CGs by being there Thursday morning at 9AM…forget doing that on Friday.

We are no reservations types and even last summer it worked out with 2 big rigs…should be easier with only one this summer despite it being busier than normal. Helps that we are fully self contained for a week or more.

As an add on, we have a reservation for every night we will be on the road and a plan b to deal with the unknown. Have a great trip!