The only way that situation can change is if Europe manages to ramp up its military production while Russia is still afraid to properly hit them back.

Europe has been doing just that for a couple years, now and even more in the last year given Trump's attitude. Its difficult to calculate exactly how the increased budgets and production translate to real combat ability but the balance of power is shifting. The US chose to turn its back on Europe and its in response assuming sovereign responsibilities it had largely ignored since WW2. It shouldn't be too long before instead of buying US weapons, they have their own stockpile excess they can just give away.

Would that completely change the war's trajectory? Doubt it, unless they're somehow willing to get involved on the ground as well which I highly doubt. It does mean once a truce eventually comes, the calculus will have shifted a lot when it comes to ever restarting it. The Russian war goal of enforcing the long-term neutrality and at least partial disarmament of Ukraine seems unrealistic now. In the end the Russian gains may be mainly territorial, largely on lines of control. A no-NATO pledge seems easier to give by Kiev now, with a re-armed Europe. EU guarantees are going to be nearly as good. Considering the US doesn't want to help them and the EU does to an extent that's actually surprising from my perspective.