Pool Covers (Particularly During Cold Weather)

I think, if they choose not use thermal lots, and wish to keep their sims alive, most people including myself would be more than happy to build a pool that conforms to the covers' size (provided that it is generous enough to allow room for ALL of the pool activities available from ALL packs). If they can dive, use the slide, a floaty and woohoo in that pool without error than that should be the largest pool cover.