If worst comes to worst I can make it work. I'd have to move the pool table in the shop.
The 10' would be ideal for my purpose.
I'm travelling to Uruguay in November to collect fish (cichlids mainly). They're subtropical so I'd be able to keep them outdoors in the fall/spring/summer here (Washington) but the winter is a bit cold. 60's is fine, even down into the 40's for periods.
I may try some heavy duty DIY insulation under and around (maybe put the pond on wood pallets filled with insulation under the pond?) with a cover and see how the temp does. I'd still have to heat it, but hopefully minimally.
Who knows. I still have time. Maybe I can find a free house on Craigslist to put it in....