Ukraine cannot give up Crimea, there is too much gas and oil off-shore, They could sign an agreement to allow Russia to rent port and shipping space for commerdial shipping rights. This would satisfy Russia’s desire for a significant warm weather port, while restoring Ukraine’s oil and gas rights that were stolen in 2014. A resonable compromise returning to some aspects of use of Crimea pre 2014, except that Russia would retain NO rights to have military equipment or forces on Crimea.
That would be the optimal resolution. Maybe whomever is ultimately in charge in Moscow will do what’s right, and will agree to such proposal.