How long you can go wetting a diaper depends on how absorbent and thick the diaper is.
The thicker and more absorbent the disposable diaper is the more pee the diaper can hold.
When I wear a thinner diaper I can usually wet the diaper at least 3 times and need to change the diaper after 2 hours or so.
But with a thicker adult diaper such as an ABU diaper I can wet the diaper around 7 to 8 times without needing to change and sometimes I'll wear the same disposable diaper all day even when wet.
I will also sometimes sit down on the toilet and continue to pee the diaper even when it leaks out the diaper because I love wearing wet diapers and love the diaper even more when it's very wet and pee is running down my legs.
When I'm outside when it's warm out and in my fenced in back yard I will wear a very wet diaper and continue to wet the disposable diaper even when it's leaking because it's a great feeling.
I will go out in my backyard that is privacy fenced in and play outside in just a diaper and shirt and I love it when the diaper leaks out and since it goes out on the ground it's not a problem.