I know that you're past this point, but I was up and walking within 12 hours of my surgery. My IV and cath BOTH needed to be re-inserted because while I could walk, I still couldn't pee. The put in the cath and more than two liters of urine came out. I have never felt so good after peeing in MY LIFE.
Just take it easy for as long as you have to, and do not rush into anything. It's a HUGE surgery and your body totally needs time to heal.