GP was talking about "having thrown away a workable peace deal", which in this context almost always refers to the purported peace deal that fell apart in 2022. In any case, the only other peace deal that is currently officially on the table as far as Russia is concerned is basically the same.

What's actually workable in the end depends solely on how far the West is willing to go, IMO. There's no realistic scenario in which Ukraine retakes all the captured territories without direct Western military involvement - air at the minimum - which is certainly not politically tenable in either US or Europe (although my personal opinion is that both will eventually regret not getting directly involved now, because they will be forced into a larger war later anyway).

Russia will definitely not give up Crimea without getting military defeated there; quite aside from any military value of Sevastopol, the symbolical and political value is just too high, especially for a regime that desperately needs to be seen as "patriotic" by the populace - that is their only real source of legitimacy in the absence of real democracy. Abandoning LNR and DNR would be easier in some ways, but harder in others because the government agitprop has already spent so much time vividly describing how "Ukrainian Nazis" are supposedly ethnically cleansing Russian speakers to justify the invasion, abandoning them now would also be very costly in terms of popular support.

OTOH I could see the pre-2022 de facto borders as something Putin would accept. They could still justify the war then by claiming that, at least, LNR and DNR were "rescued" and are now safe from further depredations, and that people from other regions that couldn't be "liberated" will be resettled, so - mission complete, oooorah etc.

However, I don't see why they would do that if the West keeps dragging its legs on military support to such an extent that Ukrainians can't even reliably hold what they already have. The way things are going, Russia can keep doing what it's doing, even despite the insane cost in human lives, for longer than Ukrainian military can hold the line. Ukrainians have less of basically everything - artillery, drones, people. They make do by making much more efficient use of what they have than Russians do, but it's still too skewed to be sustainable.

And meanwhile the West hasn't even drawn any clear red lines on how much of Ukraine Russia would need to take before the support would be seriously ramped up - if at all. So then, when Russia sees that support is already at levels insufficient to sustain Ukraine, and it's likely to dwindle significantly with Trump, and it has the upper hand in terms of momentum right now... I don't see why they'd suddenly want a deal.

OTOH if US and Europe doesn't get involved directly but start treat their role as the "arsenal of democracy" in this conflict seriously, it might just be enough for Ukraine to hold the line in the east and in Kursk. And then they might be able to trade that captured Russian land for a peace deal with some concessions - maybe not quite pre-war borders, but at least push the new border away from large cities like Kharkiv and Kherson. However, any such deal would be pointless for Ukraine unless they get proper security guarantees; and, given the whole history with Budapest Memorandum, the only guarantee that Ukraine will actually believe in at this point is NATO membership. AFAIK that is the main reason why popular support there is still in favor of continuing the war and rejecting the current Russian offer - they elected Zelensky largely as a peace offering to Russia and effectively acknowledged the de facto existence of LNR and DNR, and all they got for that is an even larger invasion, so it's a "fool me twice" kind of deal now.