Taric drops down to small size, then he places the appropriate robe for cold resistance over his body as best he can. He then starts to move very carefully down the corridor, relying on his dark vision and low light vision abilities to allow him to see. Of course, he muses, it is possible that the darkness is magical, in which case he may still be unable to see. In which case, he will need to rely upon the casters in the party once again.