russian losses, economy, production cannot go on more than some 3-6-12 months

Absolutely, Russia is already slowly collapsing, and it will get a lot worse in 2025. I'm guessing around summer or autumn so many things in Russia will disintegrate that they can't continue effectively anymore. Real estate market can collapse at any time, collapsing the financial market, but the financial markets are already so hard stressed it's basically the same as if it was collapsing. In practice neither people or businesses can borrow money.
bankruptcies are already high despite a heated economy, and this will only get worse as inflation rises. Russia is beginning to price regulate to keep inflation in check, but that will only lead to shortages and more bankruptcies.

There is no way Russia can continue this war and get its economy together. The cracks are showing everywhere now. Air traffic is having safety regulations lifted to keep flying, and just the other day, 2 passenger planes had to emergency land, because of engine failure.

Russia is out of options and out of reserves, from this point the decline will only accelerate.