For the kind of adventure you describe, it would almost certainly be appropriate to "break the rules" with regard to healing surges. I have no idea how the adventure is laid out, but I imagine it might be set up in scenes that relate to events in the earlier trial. If that's the case, then the re-enactment is occurring in a sort of accelerated time, and I'd feel very comfortable providing both action points *and* healing surges at certain milestones during the events. (i.e. not the full benefits of taking an extended rest, but reduced benefits for making progress in the timeframe of the original trial.) If the original trial was only a day long, perhaps you could introduce a "recess" in the court that occurs after every few encounter-equivalents--this would be the milestones, and is another "you have longer to catch your breath, but still not long enough" kind of mark.
In fact, the above sort of measure seems to me that it very much replicates what it sounds like the original did with potions--providing feedback to the characters as they progress that allows them to keep progressing.
The final option, of course, is to just make the players husband their resources very very carefully. If you go this route, I think it is appropriate to give the players meta-game knowledge that they are going to be heavily constrained, and that they're going to have to be as efficient as possible. It's probably appropriate to provide that information regardless, unless it's important to the tone of the game that they discover it on their own. But in that case, recovering healing surges during the adventure is practically mandatory, so that the players have time to realize what kind of situation they're in before they're completely drained of resources.
That's a very neat sounding setup, really. I'll have to look it up. (And, because it's so neat and unique, I am thoroughly convinced that it's the kind of place where bending the rules on surges is absolutely appropriate, especially when nobody has much experience with the new system yet.)