You know I think you could be right about the brake fluid over heating and thus causing the clutch problem
My Brera 2.2 has had the clutch drop to the floor just twice - each time right at the end of a half track day when the front brakes are very hot. The first time it happened, during the last lap of the session, the clutch just sort of gradually slid to the floor. A bunch of us had a look at it but couldn't figure out the problem.
I got the car off the track and called the AA man. Was slightly embarrassed when he simply reached into the footwell and pulled the clutch pedal back up - it stayed in place and operated fine. Of course, by now the system was fairly cool and operating normally.
He said that this clutch drop happens a lot on VWs, something about the clutch fluid being forced past the seal so the clutch pedal ends up in the wrong place. Think he said it's related to the clutch and brake being fed from the same reservoir. Of course, he didn't know the car had loads of heat in the braking system at the time the clutch dropped... wouldn't want to take one of those VWs he was talking about out on a track day!
Like I said, it happened again on the very last lap of another half-day's track action - clutch started to drop before I started the cool down lap. Pulled off the track, pulled the clutch back up and went in to the award ceremony. By the time I came out 20 mins later everything was perfect and I drove home 50+ miles with no issues.
So yeah, I think you've got excess heat in your brakes
Brat Pack no.8