I appreciate all the recommendations. I will have a VB plan for my feet.
I did consider the NEOS, which look really cool but were pretty expensive. I like the stabilicers, but I thought they might wreck my snowshoes. The insulated ones are almost 3.5 lb and while the tall uninsulated ones seem really cool I can't help but feel that I'd need more warmth. Also, they're pricey. So I decided against them for now, but do see their value in a well stocked arsenal.
I went shopping at Dick's yesterday.
I browsed the hunting section and I tried on some cheap -40F Quest boots with removable liners for $45 which seemed fine. But with these, I felt like I would need to carry another pair of boots in case they got too hot. This goes against my (bpl inspired) philosophy.
Then I spotted a pair of Keen -25F primaloft boots which were nearly identical to the Targhee boots I wore into the store. I knew these would be comfortable for me and they were actually my size (whereas the ones I wear regularly are a half size too large) Best of all they were more than half off at $60! So it didn't take me long to decide that with these I wouldn't need anything else. I have gaiters to help out with their height. I would prefer a removable liner, but as I said I think -40F would be overkill. Also the Quest boots made no mention of breathability and I know that the EVent used in the Keens is pretty good. If they had been regularly priced, I might have gone with the cheaper single purpose boots, but these seem like a good fit. I also expect I could push them under -25F in a pinch using the VB techniques suggested here.
So, again thanks to everyone who chimed in. I appreciate that my newbie questions get such good attention here among SUL gurus.