Remember, it's "delivery by Dec 31". We've already passed the point of possible delivery for a lot of people, i.e. International customers.
It's a tough row to hoe, but they can still make it for most of the planet if they ship in the next couple days.
Express out of Montreal in time to catch the PM flights over the Atlantic ... North America and Europe easily, even if shipping Saturday. Most of Asia too. Major cities in other places probably as well. Not cheap, but possible. I'd expect that covers 90% or more of their orders.
Delivery as far as HashFast is concerned is delivering it to the courier to bring to you. The terms were EX WORKS, so once the goods are loaded up on the FedEx/DHL/UPS truck, HashFast's obligations have ended. There's a whole bunch of other scummy stuff in the (multiple versions of the) ToS, but that is pretty standard. It really isn't HashFast's fault if your unit gets stuck in customs in Upper-Tzatzikistan for an extra week. Now the two month delay from October to now is another story, but that's pretty well covered here...