Is 30 minutes really the magic number or did you just get lucky with a better block? I've eaten plenty of cold cheddar that tasted perfectly fine, so I'm not sold that temperature is the big villain here.

Seems like a lot of fuss over one book.

My buddy did the exact same thing last summer, Chicago to Nashville on the overnight, and he ran into the same problem with the 6am drop. He ended up walking to a Waffle House that was luckily open 24 hours, killed like two hours there just sipping coffee and watching the weird late night crowd. If there's no Waffle House around, he said he just posted up in a hotel lobby near the station and nobody bothered him, free wifi and clean bathrooms. Bus stations themselves are usually open early too, so you can just sit inside and charge your phone instead of paying for gas station snacks. Next time he's bringing a book and a hoodie so he can nap in the lobby without looking homeless. That trick alone saved him from another miserable gas station morning.