Hammer agrees with Athens80:
http://www.hammernutrition.com/knowl...ions.1279.html

Having a good dose of carbs about an hour before the start will increase the rate of glycogen usage, which is what you want. Eating the main carb meal (300-400 carb calories) 3 hours before the start replenishes your liver glycogen and ensures your ride to the start will be without consequence for your race.

Too bad that you can't drive to the start and set up your trainer beside the car. For a TT this short, you will benefit most from almost an hour of warmup as close to your start time as possible. It would make a difference. When I have to bike to the start, I sign in and then cruise and do a few short hills, like 1.5 minutes, at the effort I expect to make during the event, then arrive at the start just a few minutes before my time.