I usually switch to propane while still in my driveway, a few hours (or even a full day) before I drive, just to ensure that the fridge "stabilizes" on propane, for the drive......
Be Safe, and Everyone Goes Home,
2014 RAM Laramie 2500 w/6.7L Cummins Diesel and Automated Safety Hitch
2016 377RLBH Jayco North Point
300W of Suntech Solar w/Rogue MPPT Controller & Xantrex 2000W PSW Inverter