Do you not get delivery to fill your propane tank?
If people have propane to heat their house around here they typically have a tank on their property that holds hundreds of gallons. That tank is typically owned by a local propane delivery company that comes around on a regular fill up route based on your past usage.
I bring the 20 gl tanks in for fill up. Initially started with the (portable) 6500 kw generator and enough fuel to get me thru 1-2 wks. It is, after all, NC.
(Don’t like the weather, wait an hour). The 20 gl is about as big as one can fill + still transport. I should look into a permanent tank.