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.
If you want to be able to switch suppliers depending on who is the cheapest then you have to buy your own tank.
My daughter’s house had an existing tank in the ground. It think it hold about 600 gallons(not sure).
Fortunately, the previous owner had purchased the tank when he built the house.
In most cases around here the propane delivery company owns the big tank that sits on your property. Then you can only refill the tank with gas from that company.