Some of this advice might not fit your situation but since you have a few years to go-
Save as much of your income as possible so that you have a cushion when you start.
If possible save any profit from your house sale as backup money in case you don't like fulltiming and for your life after fulltiming.
Think about whether you'd be happy renting or buying an inexpensive small condo after fulltiming.
Don't buy a new RV until you've been fulltiming for awhile. You may find that it suits you fine or you may decided on something completely different.
Whether fulltiming is less expensive, more expensive or the same as living in a house depends on many factors - how much you drive, where you stay and what you do. You can definitely spend a lot less but many people are not happy with that type of lifestyle.
Fulltiming for us means that we get to see friends and relatives more often, stay in moderate climates, spend time in beautiful areas, visit historical places and have new adventures everyday. We've never regretted our decision to fulltime.
