$2500/month is a reasonable number but way too much variability to give you an idea if that will work for you without telling us how you want to travel.
- A DP is one of the more expensive options.
- How many miles do you want to cover per week/month?
- Do you do maintenance yourself or hire it all out?
- Do you stay for a week/month at a park or only a night or two or boondock for free?
- How much will you spend on tourist attractions?
- How often will you eat out?
- Hobbies that cost money?
- Will you be keeping the house and associated items?
What we did was took our household budget and modified it to reflect our estimate of what we thought our costs will be. That came out pretty close.
A few thoughts:
- It's full time not a vacation, you don't have to put in 2000miles per week. We shoot for 100-150miles per day 2-3 times per week with occasional week/month stationary.
- We've done the boat thing also. You don't need to cross oceans to take incredible trips. Google the Great Loop. It comes with it's own challenges but no need to cross oceans on a 40' boat.