What rule is that? I've never heard such a rule. I know Dean has gotten snakes shipped from Don before when it's been in the 20's. When you appropriately pack a box with foam and heat packs, it's not a big deal.
And I know you were frustrated with your package being late, but I have a few comments to make.
First of all, are you sure that your seller selected priority overnight? There is also the option of selecting 'standard overnight' which is cheaper. Also, if you're not close to the FedEx hub by the airport, 10:30 delivery isn't always possible even with priority overnight.
The dispatch location where the trucks come from is less than 5 minutes from my house... so I know distance wasn't the issue here, and the snakes were on the truck at 7am
FedEx is the only company right now that legally allows reptile shipping. Irate snake customers calling them and bitching every 15 mins is not a good way to go about things. Unfortunately they hold the upper hand as far as shipments go, and the terms. All certified shippers know that if they fail to deliver a package on time and the snakes die---we as sellers have to eat that cost. It sucks, but that's something we have to deal with. I shipped a box of snakes to Trevor and sent them to the wrong damn address, and had to call FedEx to get them to redeliver. First off, all those folks at the 800 number will argue with you that shipping snakes is illegal, but when you calmly explain that you have a waiver and explain the circumstances---they're much more helpful. In that situation, Trevor had his snakes 30mins after I placed the call. Niceness goes a long way. We can't afford to piss FedEx off or we'll all be illegally shipping snakes and hoping that FedEx/UPS/DHL don't open the box to see what the issue is.
I've got a notice on my website under terms where I mention that if there is ANY problem with the shipment to let me know, and let me handle it. I'd rather myself call FedEx than a customer who is horrified that a package is late.
And personally, I'd be very careful about freaking out at a driver. They are the folks that deliver your package. Don't want to give them any reason to be 'late' or 'misplace' your package.