whether the sender and receiver are both in what the mail service considers a major centres. If you are sending from a rural address to a rural address you can expect the maximum wait no matter which country starts the sending process.
I live in London. I'm pretty sure that's a 'major centre' ;-) I have no idea how big Sasquewitchywitchy*keyboardmash*etan is, but I get the impression it's not enormous.
(I am, by the way, taking the piss out of my inability to pronounce the name and not the place itself. I bet it's a lovely place, but I am too stupid to say it!)