I don't think the Russian military is going to be in a position to be invading any Nato countries anytime soon.
Why invade when you can draw into your circle of influence by other means - see Orban & Le Pen? It is forgotten that this, (absorption and neutralisation through corruption blackmail and meddling) was the original pre 2014 plan with Ukraine, it is just that the corrupt oligarch of Kremlin choice wanted to hedge his bets and fucked up.
Ukraine also shows how the softly-softly approach to empire can also go dangerously wrong.
Putin and his circle have the aim of ending any opposition to an eternal Russian Empire, which they see as a historic and holy task. It is inspired by Ilyin, and influenced by Dugin and others. As such Putin sees his empire as akin to manly, virile Rome - set to dominate and destroy effete, “Greek” Europe.
As this is a “holy” mission against “degenerates, homosexuals and satanists” (who are simultaneously both “cosmopolitan” liberals and Nazis somehow) anything is justified to debilitate, disrupt and ultimately destroy the enemy. The fact that this also serves the material interests of the mafiosis that make up the Russian regime is an added bonus.
Seen from this perspective of “eternity” rather than “progress”, Putin is not in a rush.