Keep fighting a war they might (probably) lose, or sign up to that deal and guarantee to lose. Giving up their entire fortress belt, restricting armed forces size, no more weapons and western planes ejected from the country. I'd give Putin a week before he has another run after Ukraine signed the deal as is. It's worse than getting US support dropped.
Not saying there's an easy solution, but it's insane what they've proposed and not surprising it was translated directly in Russian. They don't need Western support to an extend to win it all back, they just need to be able to be able to take something back so Putin will take what he's got. As long as Russia are advancing, which they are, they don't want a deal either. Need to stop defaulting to Petrov speak that any support can be met with nuclear responses.