I have had the understanding since already around summer 2022, that the Russia is completely all-in. Putin sees it so that the Russian Federation equals Putin. For him the loss of his junta means the death of the Russia. If not putting everything in play means your junta will be toppled (that is, in your eyes: Your country will be destroyed for good), then you will absolutely put everything in use. After all, what use is it that you've saved some tanks in storage if your country gets destroyed for good?
They might hold on to a part of their tanks for a couple of months or so, but quite soon they will be on the front as well.