How did you make em so perfectly round??
I did something on my last camping trip (by accident) that turned out so well I'm starting to do it all the time for burgers. I made up all my patties in advance. 85% ground beef - angus if possible, Hidden Valley Ranch dip powder, 1 tblsp worchestershire, 1 egg. I wrapped each pattie in waxed paper and put in a vac bag and froze. I did this several days before we left for camping.
When we left I chucked them in the ice cooler and when they thawed I grilled em. Best farkin burgers I ever cooked. I liked how they were compressed by the vac sealer.
Same trip- I did something similar with steaks: I rubbed them with Montreal Steak seasoning and vac sealed, then froze. Awesome steaks.
This helps your ice last longer and they thaw slowly. Good eats.