For NYE, I will be wearing blackwatch trousers with my dinner jacket as well. Black bow tie and cummerbund. Tartan trousers are a nice touch, but a tartan bow tie/cummerbund/pocket square is a step too far, IMO.
The original poster need not concern himself with being overdressed, particularly with how he plans to wear the tie.
Far too much is being made of the simple wearing of a tie. Wear one wherever and whenever you wish, in good health.
OP, a slimmer width tie is fine. Stay away from an overtly skinny tie.