The OP said "I started at a 40' diesel pusher and have trimmed it down to possibly a 34 - 37 because so many people have said getting into National parks and maneuvering around could be a challenge." My posts dealt with debunking this 34-37' idea for NPs and other public CGs which 15 years ago I made the mistake of believing. After a week of being cooped up a RV because of bad weather a bigger RV may be cheaper than a divorce. Twice the husband, on 1/2 the $$$$, in 1/10th the space comes to mind.
No, you do not need a DP for full timing, but it appears the OP started at 40' because of the many things he wanted in a rig and at that length it will be a DP.
