Recently I've noticed that I'm not getting heat our of the floor vent, at least on the driver's side. When set on floor only, warm air is still coming from somewhere as the cabin gets warm, but my feet stay COLD. The other settings (dash, defrost) work fine.

Anyone else have this issue, and a possible resolution?

It's a 2012 SV Premium, 113k miles.

The door's to change the modes are likely worked by an actuator with an arm. Either the actuator stopped working, or the arm is disconnected. Gonna need to contort to find and address these problems. Have someone there with you so they can shift through the modes, might help you locate narrow down what is and isn't working..

Thanks! I'll go limber up. Might take a few days....

These are often VERY difficult issues to resolve. Just FINDING the problem is, as mentioned above, a two-person job...during which, if you're lucky you'll see the problem, i.e. "Hmmmm, that little door isn't moving....". THEN you get the 'fun' of literally tearing the dash apart to get to the unit, and then you get to do some more investigation - is it just a linkage issue? Motor driving the linkage? Or electronic unit? And then you get to replace and test it (often very difficult with half the dash torn apart) and then put everything back together.
At $125 per hour at a dealer...the cost racks up fast, but frankly it may be worth it.

Good luck! Being in NY, I am sure you want/need your heat!