I had the same surgery as your wife, and in Ireland, I spent over a week in the hospital (actually, I spent a month, but it was because I also had other unrelated issues). I didn't have stage four cancer of the reproductive tract, but the surgeon thought I did. I had a tumor the size of an American football inside an ovary and one the size of an orange in my uterus. My whole system was also trashed with endometriosis. What looked like "classic" cancer was an extreme case of PCOS.
They send people home almost overnight in the USA because insurance demands it, and if the patient is uninsured, the government payments (if any) are way too low to cover the costs. I had a friend with no insurance who needed an emergency appendectomy. He e-mailed me in Ireland because he was operated on and sent home in the middle of the same night, even though they knew there was no one there to assist him. After all, the hospital didn't want to pay to keep him for observation.
I have had several friends now with full hysterectomies, and I can assure you that inside or outside a hospital, MOST women take at least a couple of months to recover. I might have been OK being sent home; I was up and eating the same afternoon due to a mix-up with the doctor's order, but he was impressed and happy about it. But because Ireland has something like a real health system (and I did have private insurance to top it up), they kept me another week until they were sure it wasn't cancer.
As you and your wife sadly discovered, many medical decisions are made in the US not based on best medical practice but on costs. They know people with limited or no insurance probably will never cover the full costs. Bills of over a million dollars are common, and even thirty years ago, it was the cause of 50 percent of bankruptcies when I worked in bankruptcy court.
I am very sorry your wife had to go through all that, although honestly, recovering at home with a loving husband might have been more comfortable for her than being in a US hospital.