'If you're having lead foot problems, I feel bad for you son,
The more things you plug in, the more gas you eat up. Conserving water is another story.
Don't forget the convenience of having a gym membership that will allow you to take showers for a small fee. This is a great deal for car and van Dwellers. The electricity you use would be smaller based on having a converter/extra battery that you would need to charge daily. Again, don't let both those batteries go dead.
You could also travel to areas that are always nice in weather, but you will have a harder time finding a paid site, which might make boon docking the only plan you have.
How much you want to travel, how often you travel and what you're traveling in will change the budget.