Changing Wheel size on a 1996 Eagle Series 8

[MikeDuCharme]

Hello all,
I am new to the forum so I'd like to thank one and all who can help out with my questions.

I'm refurbishing a 1996 Eagle Series 8 pop up camper to use to travel to Triathlons and running races. My question is this: I'd like to put a larger wheel on the camper. It currently has 5.70 X 8 and I was wondering if a larger whee/tire, like a 4.80 X 12 or even a 5.30 X 12 can replace the smaller wheels?

Thanks,
Mike