Meanwhile...
The word is, plan on having ham for Thanksgiving, because there ain't gonna be no Turkey.
But Syriasly, I doubt if much will happen. Putin may shoot down a Turkish plane or two in retaliation and call it even.
He could do something way bigger, but that might (it's by no means certain) activate NATO. He could for example bomb a Turkish airbase or two using cruise missiles launched from the Black Sea.
Not that NATO wants to be activated.
And if that happens and NATO doesn't activate, that is the end of NATO as a military alliance.
Meanwhile what could Turkey do? Well, Russia's only warm-water ports are on the Black Sea and to get out they have to go through the Bosporus. Which is only 800 yards wide at its narrowest point. Nothing gets through without Turkey's say-so. Forcing a passage would be very expensive.