My local propane company said they wouldn't up my size to 500g unless I re-filled my 250g at least 2x a year. Having propane for only cooking and hot water I will not even refill it once in a year. (I pay <$60/yr for the lease).

The other option in the future is to buy a 500g tank for a few hundred. Or maybe a 1000g tank if I can get a deal.