I don't know anything about mobile phones but......
If you have a wireless laptop, then BTOpenzone might be a good plan.
It's a bit steep at £10 a day but if you're going to be offline for a couple of weeks then their £40 a month is a viable option.
Find yourself a nice quiet wee Hotel bar that is a BT Openzone hotspot. There are a few in Leeds, you can check on their website. Play poker and have some nice young barmaid bring you juice! This is what I'd do. Best part is, even I managed to set it up, they have a helpline.

You've got to watch though as some places have a better connection than others. In a Blackpool hotel, I found perfect connection in the lounge and hee-haw reception in the bar. Bit of a bugger for me as the lounge was non smoking.