Gnu's right about southern New Brunswick, the shore trip between Saint John and St Stephen (which sits right on the US border across from Calais Maine) is a nice salty drive.
Dave, be advised there is absolutely NO protection for transitting passengers whose planes land, or who change planes, at a US airport. There is a Canadian citizen, born in Syria, named Maher Arar, who was deplaned and jailed by US Immigration in NYC last year before he could board his connecting flight to Montreal, and arbitrarily deported, not to Canada but to Syria (which doesn't let you abandon your citizenship and will probably arrest you for avoiding military service if you leave as a teenager and return many years later). He has been imprisoned and tortured in Syria since then. It's getting a lot of attention.
Generally speaking, and particularly at the St Stephen border crossing, it doesn't take long to get into Canada but there can be big vehicle lineups on the NB>Maine side.
Lots to see in that area. If he has a good tolerance for cold, try taking the ferry from Black Harbour to Grand Manan Island and back.