Go slowly, don't flood. It will hold more and help you learn to feel the difference between being okay and leaking. Also, if you pee only a little at a time, the leak will be small and won't ruin your furniture or clothes.
It can take quite a bit to overload a high quality diaper. I once wore a bambino bellismo for over 13 hours when Star Ward The Old Republic came out. It held up to several cans of soda and had room to spare. I changed because I needed a nap and I don't go to sleep in an already wet, much less soaked diaper.