Why not register it in MT? , that is where many FT RV's register (no sales tax, no inspections, lifetime plates on some vehicles). You form a MT LLC that owns your expensive wheels, and the MT LLC registers them.
Domicile State rules may supercede (that is why many retirees use SD as a domicile... very simple: one overnight stay / lifetime for a tax free state domicile). Be smart, follow the rules. Very ez if your vehicle is gone more than home. Some of my vehicles live at "Boarding School"
I definitely would not be registering ANYTHING in CA if I planned on moving away. $$$$$$$ + CARB
FL insurance might be really high.