I have a similar issue. My wife and I run a food truck and run internet for the Square Register through our phones. I don't have unlimited data, and similar to DougLSmith, I'm ready to start selling when I turn the Square back on after being closed for a few days, so the inability to defer updates causes us issues with starting to sell and eats through our data.
As a UX designer by profession, upon booting, I would expect a modal to pop up saying "A software update is available. Would you like to update now?" with "Update Now" and "Delay Update" buttons. "Delay Update" would then go to some kind of scheduler.
