michigansandzilla,
Our 29' 5th wheel has 46 gallons of fresh water, 40 gallons of gray, and 34 gallons of black capacities. We also usually have a blue sewage dump tote tank on the back carrier I made for the 5th wheel. We actually can stay as long as we want on a site without FHU's if we use the tote tank to dump each week or so and the refilling of the fresh water tank is no problem either as what does it take to fill a blue 5 gal etc water can/container or collapsable tank and simply dump it in a couple times? We don't even have to lift the water jug as I'm lazy and have a 12 volt transfer pump that makes very short work of transferring to the RV fresh tank if needed. Fill on the truck and pump into the RV! Walla! NO lifting!
There's only 2 of us and our Siberian Husky and one to 1-1/2+ weeks is no problem at all. It all starts with common sense water conservation tactics used by all people in your RV. No excuses accepted for wasting water! When we take 2 of our grandkids or great grandkids along, we still can easily last a week in the 5'er before dumping. Yes, it sure does help if using the CG bathouse during the day when possible as it further extends tank time.
My wife is a master as far as conserving water and better than me! She usually uses only 3 gallons for her shower as first get wet, shut the water off and soap up including your hair, then rinse off completely. DONE! What's the thrill of just letting the heated water keep on running anyway??? You learn very quick when you do a lot of boating in a cabined boat as you may find yourself dropping the hook (anchor) at night more than being able to find an open slip to use! You are only limited by your imagination and ingenuity! Where there's a will, there's a way! You can lead a horse to water but you can't make it drink!
Our TC has 40 gallons of fresh, 20 gallons of gray, and 14 gallons of black capacities. Really no problem as the TC goes where the truck goes and it passes the dump station at least everyother day as we take lots of day trips. These are the 2 RV's we take most of the time and are extremely comfortable!
One of the things we really don't like is the full hookup sites are almost always jammed together so it's like parking lot camping. We like elbow room and lots of trees and above all, some reasonable privacy!