Dismembering it would be wildly impractical for most provinces and republics

The opposite is true, it is wildly practical. Many regions in Russia want self-determination as the Kremlin regime has sucked their areas dry and siphoned it to certain privileged loyalist areas. Western policymakers should build partnerships and project soft power unto these regions that are ripe for self determination

and would 100% be ammo for those that do say the evil West wants to destroy Russia.

We should want to destroy Russia. The only thing that is evil is if we don't destroy Russia. This pseudo imperial state is built through conquest. The days of business with Russia are over.