I mostly boondock for weekends and I always use the refrigerator. As said above if possible leave the RV plugged in to shore power for a day or two before your trip. Run the refrigerator on electric and fill it with pre-cooled foods from your house refrigerator.
When you are ready to depart on the trip flip the refrigerator to gas and go outside and put your ear to the exterior compartment door and make sure you hear a dull roar from the flame.
Go on the trip and enjoy your new found cold food including ice cream if desired. When you get back home put the refrigerator back on AC power.
As far as propane use I've never even thought about it. I have two propane cylinders and an auto changeover regulator. In the 15 years I've owned my trailer I've probably only filled the cylinders 10 times. If a cylinder runs out the regulator automatically switches to the other one and puts up a red indicator to let me know so I can get a refill when I get home.
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2001 Suburban 4x4. 6.0L, 4.10 3/4 ton **** 2005 Jayco Jay Flight 27BH **** 1986 Coleman Columbia Popup