Well, if you ask me I bet you'll be fine.

I've been watching the TdF. If a rider blasts off one day, he's likely to flame out the next unless he's a GC contender. Richie Porte is a good example of that.

So I'm guessing that instead of pacing yourself for a day at a time, you'll have to think more globally and think of your pace being stretched out over the four days. Or so it seems to me. Ride the first couple of days really slow.

Good luck.