I can't comment on how the event was as I didn't attend, but as I did do a HPDE in June, I can comment on charging at Calabogie.
Your concerns are very valid! Charging was a losing battle over the course of the day.
On my HPDE day, there was only myself and a Model S that showed up so we had to share the 100A circuit by lowering our charging rate to 40A each. The 3 hours of track time was broken up into six 30min sessions with 30min breaks in between and a 1 hour lunch.
Charged to 95%, I left Kanata and got to the track with about 70% where I quickly found the chargers and plugged in. Fortunately, the novice group had to do a classroom session so that added another 30min of charging before I actually got on the track. I was at about 90% when I first hit the track. The first couple sessions were a learning experience to orient yourself with the course so I wasn't pushing the car hard and there was no passing. Each of those sessions used up about 15~20% and a 30min charge was only giving about 10% back.
Once I was able to push the car, I was using 25~30% per session. Heading out for the last session of the day I was only at 23% and ended it short when the car hit 15%. From there I waited to charge back up to 30% before I headed home.
Even if I was the only car there and could charge at 48A, I don't think that would have made any real impact over the 40A.
I'd say I was fortunate that there was only two of us there because any more and having split charging time would have ended the day much sooner.
It also doesn't help that power output is impacted by state of charge so it was unfortunate that my best SOC was being used up during the leaning sessions.
Don't get me wrong, I had a blast taking the car out, it was so much fun to see what this car can actually do.
I recorded the sessions on a GoPro mounted on the tow hook. Here's one clip:
I've never done any video editing before and GoPro likes to save the files in 8min clips, so this is just one of those clips.
