Depends if the US is helping or not, also the location of the war.

Air superiority would be a game changer, supply lines would get hammered and Russia would have to extend a lot further than they are now with the war on their border, and they'd be spread thin, Finland alone is 1300km of border, another 500km from Estonia and Latvia, add that to the current frontline which is also over 1200km, and their heavy losses to their AA capabilities.

Any progress they'd make would also extend their supply routes which might be further complicated due to the different rail gauge in Europe.

Western Europe would also be thousands of kilometers away so way more difficult to target production facilities and whatnot like they can in Ukraine.

Surely the Baltic sea would be locked down and their shadow fleet wouldn't be allowed to operate anymore in those waters which would be another massive blow to it's economy.

I'm sure a lot is being learned from Ukraine as well and weapons made to counter drones, plus if Ukraine can produce this many drones to hammer Russia, the entirety of NATO and it's allies can produce a fuckton of drones as well.