Of course, Russia wouldn't allow Crimea to be retaken. Though I suspect you didn't ask to many Crimean Tatars in your cross-section of Crimeans. But unless Ukraine takes Kherson and pressures Crimea- Russia would be uninterested in talking. Should Ukraine fail to take Kherson(possible) then it can be expected Russia will push onto Odesa. So Kherson, not the East, is key to the outcome.