Big Bear Mountain and Dragonflier at Dollywood both have 36 degree operating temperatures so I wouldn’t be surprised if that’s the same for Snoopy’s Soap Box Racers. I also believe it’s on the park for deciding what temperature to run it in because I know Energylandia runs their family boomerang in negative temperatures and snow. The park was also testing Racer in the snow last week so maybe they will run it in colder temperatures.

Just based off personal experience visiting two competing parks that are only an hour away from each other. The park with the most rides / coasters running had a higher attendance. Here is a trip report from visiting both KD’s Winterfest and BGW’s Christmas Town:  

Could the first 2 iterations have lasted longer had there been more rides.... My understanding is the 1st iteration attendance dropped every year to the point it wasn't worth doing. We all know why the 2nd iteration happened... I totally get the seasonal atmosphere and all that jazz, but people can get that from other places as well.   Sure people would still want the event and a certain percentage would show up regardless (meal and drink plans LOL), but if next year they announced no rides, watch what happens to attendance. People think rides with KI.  If rides were not important, they wouldn't be adding rides to the event.

If memory serves me correctly Flight of Cheer is fine but in the past it had to be above freezing when they started running Mystic Timbers.  It could go below (29 - 26) after it started but the if the temperature was below 32 at park open, it would not run.  I would believe the same would be true for The Racer and soap box racers, but haven't heard anything yet.

I have to point out that I believe the first 2 itterations of Winterfest had no coasters and was still so popular that people wanted it back.   I believe most people go for the atmoshpere.  Then comes the food with the meal plans.  It will be cold this weekend, but I'm pretty sure it will be crowded.  People gotta eat