The other thing you need to think about is the possibility of a B gate at T2, they are more usually long haul but I've had them a few times recently on early departures on LX, OS and LO - LH might use them too but I haven't been on LH recently in the early morning. It's a fair walk. Gold track is often busy in the early morning, there are something like twelve departures in the first hour from T2 and nearly as many in the second one so just think about 3000 people making their way through the terminal at the time you are!
With no priority I would not allow less than 90 minutes and the one thing staff in T2 are really strict about is gate closure not less than T-15 and sometimes more and there is no flex on this at all.