Min room size for Wilson Audio Sophia or WP8

If you are able to make any changes in the room by adding (record) bookcases on one of the 14' lengths, the room should "see" itself as 13' x 14' x 8'. That could be helpful. As far as the speakers, I had WATTS from '86 to '93. Unless you have a cut with deep bass in them, the room will support the speakers. Remember that, if you listen to vocals - and one ones from current times, which add reverb, sound effects and bass to the mix, and you listen to older singers (Ella, Sarah, or whomever), there is no "mixing" in their voices (they wouldn't allow it!) and so you'll be listening to unprocessed jazz singers. The room will do find.
If you listen to things like "The Patriot Games" soundtrack, it might overwhelm your room.
I once put my system in the basement, which, although the ceiling is only 7 1/2' high, by putting insulation in between the joists, it made the ceiling seem "invisible" to the speakers (also absorbed bass running along the ceiling) and since the room was the length of that house (25 x 45), the sound was pretty dazzling. Room size counts, or as we like to say, "Size DOES matter." But only for reflections, not size itself. Remember, HP originally reviewed in a room that was 12' x 16' - and he had the IRS speakers!

P.S. I've had tube traps since 1987, and I assure you, what you've read about the room being too small (late as my response is to your original post) is wrong.
What's more likely is setting the speakers up at the absolute optimum of the room. And things like having the equipment stand in a corner, or the amps between the speakers will matter more in a smaller room than in a larger room.
I did have the Puppies, by the way during all the iterations I had of the WATTS, except the original WATTS did not HAVE Puppies. Dave didn't release those until last '88. I was, he told me, the first non-Wilson person to hear the Puppies. I was pretty flattered, of course, and bought them as fast as I could (which I think he knew I'd do).
I had the originally in a small square room (this was before I knew about room dimensions (around '86). They sounded great on pop music of the time (Michael Jackson's "BAD" came out a few months later, but I'm sure your room, which is bigger, will do just fine.
You can also call Wilson Audio to ask them about room-mapping of the speakers if you're still having problems at this point, a year after your first post.

No direct experience with your question, but I have A/B'd the two in a larger room. The W/P was definitely a bit leaner in the upper bass which usually augers well for full range loudspeaker use in a smallish room (and I'd call both models full range). I can't speak to what will happen really deep in the bass because the larger room in which I heard the two makes my experience less relevant to your question.

Just one more data point for you.