There is about 0 real solutions here, mostly just keeping war of attrition, which slowly drains Russian economy without reasonably allowing it to escalate. It is super bloody though, and it is not an option to choose willingly for either side.
The only thing dumber than NATO doing direct strikes on Russia is Russia doing direct strikes on NATO. This is why Ukraine not joining NATO is such a big talking point in negotiations. If Ukraine goes NATO, Russia won’t be able to exert any military control over it anymore.