Thanks for the info and suggestions. If we are on that flight, it does indeed look like spending the first night in Strasbourg may be the best option (though because our time in Alsace is very limited, it's not ideal).
For some context: our flight has not yet been booked, so we do have some flexibility. However, it's on a "thin" route with not a lot of flights available (in fact, just three flights per week). We will be coming from Corsica (most likely Bastia, but now, maybe from a different airport, see below).
The wider view: For us, this trip is not really to Alsace - getting a couple days there is a bonus, a nice little by-product of an unconventional routing on our way home. This trip is actually (primarily) to Corsica, where we will be spending 2 weeks. So our brief stop in Alsace is just the cherry on top, if I can manage the logistics. Getting home from Corsica is a bit of a challenge as we plan to use points for the long flights. So in order to facilitate that, we will be doing a positioning flight from (somewhere in Corsica) to (somewhere on continental Europe) where we can catch a good flight home (using points). Our actual departure point from Europe will be Zurich (for reasons too complicated to delve into here, but Zurich is where we will board our flights home - the long flights are already booked and I'd rather not change them).
Looking at our options for getting from Corsica to someplace close-enough to Zurich, we settled on a flight to Strasbourg, with the intention of spending a few days in/around Colmar (from Colmar, we will train to Zurich, spend our last night there, fly home the next morning). There's a cheap flight from Bastia (Corsica) to Strasbourg (that's the flight I've been assuming we would take), but the obvious rub is the late arrival. However, I think I can actually keep the destination (Strasbourg) if I change the flight origin, and that gets us to Strasbourg early enough that we get more of a usable day there...
There's another flight to Strasbourg that leaves from a different airport on Corsica - from Calvi (a few hours drive from Bastia) to Strasbourg which gets us there at 10 am. It would mean we have to drive across Corsica and depart from Calvi, which would be a few more hours on the road, but in fact that might work out just as well for us, as it would eliminate the need to return back to Bastia. That's assuming the car rental cost doesn't escalate (will check on that).
That flight would get us to Strasbourg in the late morning, I assume we could get to Colmar by early afternoon via train. That buys us an afternoon in Colmar (admittedly at the expense of an afternoon/evening somewhere in Corsica) and avoids the major hassle of a midnight flight arrival.
This looks do-able. I need to double check all the flights, and see if we can get from Strasbourg to Colmar by train or bus without a long expensive slog, but starting from the airport at around 11:00 am I'm guessing there should be reasonable train/bus/etc options.
Hmmm. This should be interesting...
