JustJack
Jack of all trades
They sell greenhouse fabric on ebay if you still want to find a way to leave them outside. It's much cheaper than anything I've seen locally and they sell it by the yard in 24 or 25 foot widths, so that might help with cost. My husband's out on disability so we've really had to watch our spending too. I don't have to deal with temps that cold or snow at all so I don't know how that works--do you still need a heater if you have them in a greenhouse?