[jphughan]

I agree with the others that it's a toss-up and will depend a lot on you. I think it's likely you'll make it through at least the first day though, in which case you can change your pads that evening. But if you'll have a spare set, then no worries and just keep an eye on the current set. If you notice brake fade kicking in early (wouldn't be surprising since the heat will be concentrated in less pad volume), then swap them.

On the other hand, if you're worried that you might end up losing track time by having to change pads at an inopportune moment and/or don't think you'll have enough energy for a pad swap on Saturday night (especially given that you're using OEM calipers rather than a quick swap BBK setup), then just change them in advance. You wouldn't be leaving a ton of money on the table there, and you could potentially be saving money by avoiding that lost track time.