Yes, just make a big pile of hay. I generally make two: one from regular hay and one from a special hay they really love and seldom have because it’s expensive, like second crop or crau hay (that way, they kinda gain something from me being gone ^^), and I put their normal ration of vegetables (with some extra leafy greens for hydratation). It always went very well. Honestly, when I started leaving for business trips I was scared of leaving my rabbits alone and had a petsitter come twice a day even when I only left for 24h. But in the end, one of them broke my door’s lock and couldn’t enter the house and I realized my rabbits where actually more stressed out by having someone they didn’t know come for two minutes and give them food than by staying alone (especially since Aki can’t see anymore – she was always wary of strangers but it’s worse now). Also, I’m always worried the petsitter will forget to close the door of the rabbits’ room when leaving.
I read a lot that you needed to have someone come because when a rabbit is ill their state can deteriorate very quickly. While it is true, that means you need a petsitter who will notice your rabbit isn’t feeling well, is able to grab the bunny without injuring them and will think to bring them to the vet. I haven’t found anyone that reliable. So, when I leave for more than 36 hours I take a petsitter (I prepare everything in advance, even the vegetables, and give a very detailed care sheet – I think most of the women I employ think I’m deranged) but when it’s less than that, I leave the rabbits alone. I don’t really like it, but I think it’s what works the best for us. I wish I had a better phone to do the bunnycam thing, though, that’s really cool ^^