Urgent! Job offer at Sainsbury's

Hi there,
I've been offered a job at Sainsbury's as counter assistant, 12 hours a week and the hours are pretty good for me.
However, I'm in a sticky situation as the Sainsbury's is in my university town, of which I'll be leaving in mid June to go home for the summer. My job at Sainsbury's depends on whether I can work over the summer and obviously I cannot live in my university town over the summer, as its expensive for a bnb and the rent for my house next year doesn't start until September.
My hometown where I will spend the summer is not commutable, it's 3 hours away. This job is literally perfect for me but the only snag is the summer part, any advice? Particularly from those who worked at Sainsburys before.
I understand it's unfair on the management to swan off for the summer, so I can see why they want you there, is it possible to transfer my job for the summer months to Norwich? (my hometown)
Any advice appreciated.