One article that I read stated that the tunnel is so cramped in at least one area that tanks cannot be worn. That severely limits options.
Attempting to "widen", which would have to be both vertically and horizontally, has difficulties and risks - chiselling in such cramped quarters would be difficult to impossible, chiselled-off stone would have to be cleared out to have any benefit, and a cave-in would be lethal to rescuers and rescues.
Being stuck for a few months appears to be the least-sucky option, so far.