Single breaker, split wire that is inaccessible and one wire not working
If the bedroom power is being daisy chained through multiple outlets, I would physically check the wiring on each one.  I have encountered problems with backstabbed wiring several times.  Last time I fixed something similar for a friend.  Their power was daisy chained through 4 backstabbed outlets.  The third one in the chain was the problem.  It even tested good with a non-contact voltage reader.  It turned out to be an intermittent arcing connection.  I took out all the backstabs and wired them around the screw terminals.