recently I heard at a show the Sasha 3 DA ver. the room was overall near the cubic footage of your's.
wider but not as long.... maybe 11 or 12 by 17 to 19 perhaps.
they were set up on the short wall.
AR monos and their upper range pre had the power and control duties.
although there was a ton of lower end response it appeard wooly and unrestrained. flabby in fact.
with your power amp, this should not be a concern, although bass may end up needign some attenuation via bass treatments.
the sasha bottom end is prodigius. startling in fact.
having felt in previous years the Sophia I and II were the better Wilson's in terms of value to performance, these latest sashas are a substantial step up.
speculating here, I would say as well, the Sasha IIs would be too.
Each past audition of the wilson Sophias were driven by Ayre gear, so all SS power.
hearing these dAW models fueled by tube power I gotta admit in spite of the tags the new Wilson's are a more 'refined' sounding loudspeaker, I still believe at least for my tastes, tubes are needed in the rig somewhere for best results.
in your case if possible, setting them up on the long wall might win the day. but some experimentation there and looking into bass traps might well be in order, though if you enjoy the Wilson sound, and got the dough, I'd say go for it.
BTW, the DAW's I heard were fronted by a upper end music streamer and a dCS stack with Transparent cabling through out. wilson seems always to be somehow attached to T-parent wires. ugh! never have cared for TA wires, regardless.
regardless, good luck.