It seems the snow tires may in fact be the culprit. I switched 2 of my all seasons on front and the sound was seemingly lessened and seemed to be coming from the rear (I’m nearly deaf in one ear, so determining directional sound source is difficult). I then went ahead and switched out the other 2 and the noise was almost completely gone. I say “almost” because if I really listened, I think I could hear a similar sound while coasting in N at slow speed. That seemed to me to be a normal level of sound though.
I put the snows back on and the noise was back in force. At slow speeds it almost sounds like I’m driving on snow. Thankfully, you can’t really hear it at highway speed, which is most of my commute.
What’s interesting to me is that this “tire” noise is in addition to “road noise” I typically attribute to tires. The road noise changes its “rumble” with road conditions (fresh pavement vs old pavement, etc), but the tire noise doesn’t seem to. Perhaps the tires are scalloped or something from being run on a bad alignment (they look ok, but I’m no tire tech). The DOT date code is from 2014, so they’re not terribly old or worn out.
I did put the car up on jack stands, tested for play (none) and ran it in D1 to see if I could hear the sound, but didn’t really hear it. I also put it in D and poked around with a mechanics stethoscope, but didn’t hear anything incriminating - both sides sounded similar.