There is a general consensus within the model RR'ing community that having a massive layout will bring and overwhelming sense of satisfaction to the hobby, when really it has an adverse affect. At 43 I have a 15' x 48' layout that will likely never be completed for various reasons. It takes many of us into our 40's before we reach some level of financial stability and acquire a space suitable for a layout. By then, many of us have a wife and children which require the first block of our time, followed by whatever else we are involved in, leaving little time for any layout much less a 2k sq ft layout.
Suddenly the 12 x 12 room in a remote corner of the house the wifey granted you doesn't look so bad. It will likely cost less and be more practical to finish and you can dedicate more time to detail and still see the possible completion of a smaller layout.
Maybe you should consider a smaller build in another part of the house where it will be more manageable and easier to complete. Leave a couple of large loops in the basement to get the highballing out of your system on occasion.
We found ourselves at York on more than one occasion engulfed in some of the highly detailed 4x8 or smaller vendor displays that seem to bring the same satisfaction as a massive unfinished layout. There is satisfaction in finishing and finishing well. Good luck in what ever you decide.