Altair and Desmond were 6'0 (183cm) and Ezio was around 5'10.
The developers did say in the Inside AC3 videos he was heavier and bulkier than previous protagonists who they described as 'small guys in lots of armor'.
From playing the game my guess would be around 6'2. He doesn't look like someone who is shorter than or 6'0. Also the natives who lived around New York/Canada were described as very tall people.
Connor Fabiano is 6'.
Connor Tkachuk is 6'.
Connor Franta is 5'9".
Connor Buckley is 6' 2".
Steven Connor is 6' 2".
Sarah Connor is 178 cm.
Connor Trinneer is 5' 11".
Amber Connor is 5' 2".
Elizabeth Connor is 5' 4".
Janelle Connor is 5' 9".
Kristofer Connor is 6' 1".
Nathan Connor is 6' 6".