Hi there play.
I believe it is possible to train for the run in 7 weeks, although i guess it will depend on your age, lifestyle and general state of fitness. I would suggest that 1-2 miles 3 times a week is a good start, although i'm certainly no fitness expert.
If it makes you believe in yourself, my dad ran it 6 years ago, aged 49, with 4 weeks "basic" training. Not only that, he spent the night before in a pub with my brother in Northallerton where i was living at the time. The pair of them woke me up, slept in my spare room and subsequently finished the race !!!!!
I certainly wouldn't suggest this training regime by any means, but good luck and stay off the ale, eat well and give it your best.