Staying in Oxford For Offer Holder Day as an Under-18

I was recently offered a place to study at LMH oxford, and they're holding an offer holder day in March. I'm planning to go, but problem is I'm 17 and still will be in March, and hoping to go on my own (getting used to being independent before leaving home for real and all that jazz). All the hotels I've looked at so far don't allow you to make a booking unless you're 18 or over, so does anyone know any hotels/places to stay in the area that will let a 17 year old stay on their own?