Doesn’t Russia a enough land and empty space now
Yah, but they don’t have enough bioweapon labs.
That's like asking Israel if it needs to take anymore land from the Palestinians.
Russia's primary goal in this war to save the ethnic Russian population in Ukraine from genocide and/or being driven out of their homeland. The other goal is to protect it national security by de-militarizing Ukraine.
So, it will take as much land as it has achieve those goals. The Ukrainians could save more of their country by surrendering.
All of our meddling and talk of insurgency will eventually result in Russia taking every inch of Ukraine. We and NATO have done a enough damage and need to leave before Russia is forced to do that.