In ten minutes a physically capable person should be able to walk from HP to the front gates.
I know there's at least one restroom by Jurassic Park, one by Three Broomsticks, one near the Sinbad place, two in Seussland, one near the Port of Entry, and I believe there's one in the Marvel area and one near the Toon area. There's no reason it should take 10 minutes to reach a bathroom at Universal, much less any theme park.
Also, you don't have to walk the full way to the USO or IoA gates. About 1/4 or 1/3 of it is on a moving sidewalk.