Try a Google search under RV Caravans. Here is a link to a couple websites that may have some info for you. RV Caravan Tours - Roaming RV
and Try An RV Caravan Tour Before Committing To Full-Timing
. You may be able to join and leave these tours at locations of your own choice, and not do the full tour.
Another option is to put up a 3 x 5 card in the laundry room of a couple of RV parks near your home, and ask about forming a caravan with someone who is snow-birding to the south. Luck to you
Jim and Valerie, Workamping semi-full time, 2005 Winnie Adventurer, 2015 Subaru Forester toad, wintering in Laughlin, NV( this year )