Although climate and geographical location are bound to be major factors, and that there are multiple ares that fit the bill for a world-record bass in both departments, I think we should instead put more brainpower and thought into what type of lake or water body has the best chance of breeding a 25 lb beast. We shouldn't stop at "the lake will be small and private", or "It will be a massive body of water". What type of structure will be prominently featured in this lake? What will the topography be like on the lakes bottom? Do you think it will be a lake where it is mostly 25 feet deep, or a South Florida style with depths rarely plunging below 10? What other species will be found is this lake? Will it be a California style trout stocked ecosystem, or will other baitfish such as gizzard shad or bluegill be the main forage for large bass? Once we can decide on a consensus for these answers (which there very well may be none), we can then turn to geography and other factors such as fishing pressure to slim down the list of fisheries that fit the profile we created by answering these questions.
I personally think the lake will be no more than 100 acres in size, but more than 10. I think the lake will contain a large amount of deep water, to protect bass from the heat we have mentioned to be so brutal in the top locations for a wr bass, allowing the fish to have an extended life span. I believe it will be a trout stocked lake, such as the ones out in Cali. The one exception to this is the fish wil have to be a pure bred Florida Strain, which is becoming rarer and rarer each year, but I think still exist in some places. The lake cannot be to large, becuase we have to remember that growing the fish is only half the battle, and that tricking the bass into biting, and bringing it to the boat is still an issue.
