Yes, release the cover any way you can, even if you have to cut it away. You MUST remove the cover's pulling the walls in. The water/ice on the cover is normally supported by the water in the pool. The water goes down, the cover pulls in on unsupported walls (the water is a structural component), and the pool collapses.

Once you do that I suggest you run lines and stakes to pull the walls OUT until spring, and keep them from going in. After all, the walls are designed to resist outward pressure, just not inward pressure.

I suspect the pool is salvagable after that, though it may need to be dis-assembled partially or completely.