We took off 18 years ago after early retirement, not even knowing what full-timing was all about except for talking to some on our first winter trip. We sold the 2500 sq ft house and everything in it, paid cash for our RV, had no other debt and took off for the unknown - no internet or cell phones at that time. Invested our house sale money. Absolutely no exit plan.
Sixteen years later we devised our exit plan (thought about it for a few weeks) and bought a 1100 sq ft. small townhome in a completely different far away state in which we loved to winter. Everything worked out just fine without an exit plan for Day 1.
I think the only plan you need is to be out of debt.