Great piece.
Personally, I think what we're looking at is a false flag operation. Both sides, as you say, are tired and depleted and Putin may want to use this to "justify" breaking out bigger - more dangerous - weaponry.
If it is Ukraine, and as you say, they wouldn't carry out an assassination attempt with lightweight drones. If anything, it's probably a message saying "we can get to where you live."
But I do think, either way, this is going to pave the way for a more dangerous Russian offensive. Bigger bombs, in other words.