Judging by the clearance my trailer's fenders have, I probably cannot go much larger than 8" tires.
Yes, the spin faster than larger size tires, but if properly maintained hubs/bearings/lubrication, they should be fine.
A lot of Cat trailers I see are also running 8" tires.

I don't know about other States, but here in California, an auto, pulling a trailer, is (I believe) limited to 55 MPH on highways/freeways.

I'm using 5.70 X 8 size tires.