The Russian forces will probably take another four weeks to destroy the Ukrainian units at the Donetzk front. The Russian command will then have to decide which parts of the Ukraine it will want to keep under control. Next to Donetzk and Luhansk the region north of Crimea is a likely candidate. Odessa and Dnipro may also be still on the menu. The regions can be kept as statelets under local control or form a confederation that may well institutionalize a new country.
Anything beyond that depends on the willingness of the U.S. proxy government in Kiev to submit to Russia's demands. Russia can leave it at that or that or it can continue to mow the grass until none is left.