Westinghouse pictures show a 20 pound tank being used, and while they are everywhere, everywhere, I don't mind taking a 30 pounder out in my car to get refilled.
But...sold my tractor and my truck, so anything larger isn't in the cards. Gen would be kept in unheated garage, and PA winters can get down to zero. On really cold days I could put a small heater next to the gen and tanks and keep them warmer. Would put tank in garden cart and wheel it over to house. Broken track, yes understand cold weather vaporization issues but average winter temps are more likely in the twenties instead of zero. Of course Murphy arrives in the coldest, worst weather...
I had a 1000 gallon propane tank at my last house, didn't have to worry about this for sure, now moving into rental home which is fuel oil and electric, unfortunately.
The problem with smaller tanks is gas company won't send a truck out to fill them, so either you go large, or small enough to carry.