I know that the 20 pound (I don’t know how many gallons, maybe 5-10) propane tanks are readily available, usually used for grills and cooking. Larger tanks are available too, but not as common. I don’t know how much run time you’d get out of 20 pounds though. If you have to swap tanks 2 or 3 times a day, that isn’t extremely convenient. But better than no electricity at all.
I use a 5 burner propane cooktop (never use all 5 burners at once) and we use one small tank (10#) a month. Also use propane to heat the dryer but never use in the summer, just hang up. Cheaper than electric.