Their gains would be much less for the same expense, were they in areas where Russia expects to be attacked.
It’s the same pattern with bullies - they are always surprised when the victim is no longer forbidden to hit everywhere and not only where the bully took initiative.
Worked in Artsakh in 90’s too against Soviet and Azeri forces. Sadly the last few years (or two decades) have undone this largely.
But just like in Artsakh, they shouldn’t agree to any frozen status, or it will end just like for Artsakh. They should just keep advancing until Russia does something to guarantee their security.