fermentation time for colder dough

Good morning all,

I just finished mixing my first attempt at McGuire's Pointe-a-Calliere Miche and ended up with a dough temp of around 70 (I used water at about 62F-I had assumed greater heat generation during mixing but it didn't happen) instead of the desired 76F.  Bulk fermentation at 76F dough temp should be roughly 2.5 hours.  How much additional time would be recommended at this lower 70 initial temp (room temp is 76)?  I'm thinking 3 hours should be fine?

Franc