Welcome to the forums and you have started with a question that will get all kinds of answers, even from those that have never owned a big rig. Granted I put mine where most would not try as we are not Resort types...prefer public CGs and by the stares we get I know we are in the minority. Yes, I have some scratches to prove it.
If you look at my signature you can tell my opinion, but some history first: 16 years ago I bought a used 36' DP because of people on here saying 36' was the max for public CGs... NP, SP, USFS, BLM, COE CGs. Did not take long to realize that is not true, especially out West. Traded for a 40' DP and then (not many years later) to our 42' four slides. I now suggest you buy more RV than you think you need... ONE TIME as trading costs $$$$.
I agree with Bill S that in CA it's difficult to find sites big enough (would add the NE too), but even 36' can be difficult. Sure it's harder BUT not impossible to find sites big enough. He must have a toad that's 5' long so it will fit in the 45' site with his 40' MH, 5' is not going to make much difference in finding sites. It was easy to shrink my 42' to 40' in Yellowstone BUT 45' to 40' might be a problem.
14 years ago and before smart phones and good cell coverage it was a lot harder finding information about sites for a big rig in advance. I have found, even when a USFS CG says 30' max, I always find a couple sites that are big enough for our 42', but DO NOT show up Friday hoping they will be empty. Show up late Sunday or Monday and there's a good chance they will be empty as the working folks have left.
After the first year with a 42' I can say I never hit another curb BUT recently with our "new" 45' I've hit several. Hopefully it will not take a year to stop hitting them. Fortunately I'm able to backup (click on "How I tow" below) so I'm able to make 2 point turns where you backup a little to complete the turn. This increases where I can get without unhooking the toad.
As half timers and snow-birders, the livability for the three months that we spend in SE Fla is more important than the extra effort it takes to find sites big enough the other 3 months. I would think the livability for Full timers is even more important.
With only one post it's hard to know what the OPs plans are and usage requirements but he is way ahead of where I was when I first asked for input 14 years ago.
This post is my opinion (free advice). It is not intended to influence anyone's judgment nor do I advocate anyone do what I propose.
Sold 04 Dynasty to our son after 14 great years.
Upgraded with a 08 HR Navigator 45โ...