As it turned out, we ended up (at Daughter #1's request) at the Planetarium and bought a family membership (we'd not belonged there previously, but, as is usually the case, the cost of an annual family membership was only a few bucks more than just getting in for the day!). Both of the girls were quite into it, and we ended up being there for a good four hours, including quite a nice lunch in their cafe. Unfortunately, Daughter #2 started on "melt down" when we were in the Gift Shop on our way out ... spending the better part of a half hour not wanting anything that was "doable" and being fascinated with all things inappropriate to the occasion (a museum visit a couple of days after Xmas when, lord knows, her parents were disinclined to purchse any "toys").
So, things went from the gift shop melt-down to the not wanting to put on coat melt-down, to the insisting we find a water fountain melt-down to the "not being happy at the prospect of possibly not going to the movie given her behavior" melt-down on the bus, to the alteratively plaintive and screaming demands that we still go to the movie melt-down on the subway home. Needless to say, a lovely time was had by all (especially when her big sister figured out that we were indeed not going to see the movie, resulting in more tears and general hostility).
How much you want to bet that by this weekend The Wife will be telling me that I'd have had my Mom's place cleared out if "I wasn't in denial about it"? What the fuck does she want me to do ... completely forgo sleep and work over there all night every night? It's the only way that I can even figure having a chance to get that done at this point!