Not really. He knows that if he launches one, there’ll be ten straight away on their way back into Russia. Nobody wants that.
If you want the Chicken-Licken scenario, he ignores the fact there is European peacekeeping forces there, and goes back in for a second bite with conventional forces, to test out whether we have the mettle to react to that. Hence why the deal is so much stronger if there’s an American backstop there.
I don’t think he’d do that, but I’m guessing a bit. The fact he’s using North Korean forces (by the way, when it comes to nukes, I’d be far more concerned with Kim than Putin) would suggest his levels of army reserves aren’t great right now. He won’t want to enforce conscription either - that won’t wash with the Russian public, and as we’ve both said, he’s many things, but he’s not stupid.