Can't see either side agreeing to formal territorial concessions. Neither has such an overwhelming advantage at present that one gets to dictate to the other. Just like Korea - there's a demarcation line and the shooting stops, but no official peace treaty. Neither side is happy with what they currently hold, after all.
Devil's advocate - Ukraine getting territory back is a longer term prospect. They've lived without Luhansk and much of Donetsk and Crimea for 12-15 years already. Doesn't seem likely Ukraine has the open disregard for it's own soldiers' lives that would be required to make a large scale push in the near term to regain big pieces of territory. And a post-putin power struggle may present less bloody ways to make that happen - either the territory itself, or allow more favorable and safe terms for the ukrainian-inclined populations of those areas to return to Ukrainian held land. Human capital is extremely valuable to both of these countries given their already poor demographics trends.
The conditions for land reclamation may be better later than they are now.