I can’t remember a year when at least one session hasn’t been lost for some reason.
In my brothers 1st year he did 19 laps including the race (when they still had mornings and Thursday afternoon) that was on a classic, would have been 20 if they hadn’t done a fuel run in one session. Now the most you would get if every session ran would be 19 so you should be able to get a classic to do the distance.
Biggest problem with just one ride on the classic is the chance of it breaking in the race. If you have 2 rides at least you double your chances of getting a finish. I do take your point that it’s a big expense for just the one ride.

Either way it doesn’t matter as the provisional format is the same as this year pre disruption.