Hypothetical scenario: Trump loses and goes 'scorched earth' on his way out. What does it look like?

Donald, open the envelope. Stick your nose in the envelope. Inhale.

This thread seems to have run its course and there has been no mention of the whole Supreme Court situation. Let’s say that Republicans ram thru a new justice and the Democrats continue to threaten new rules when they take over. What might the R’s do to pre-empt those things (court packing, fillibuster, etc.)?