Virtually all Amtrak long distance trains have a significant number of riders who are up in years, because retirement is the time when people have the opportunity and the time to take these long trips. Unfortunately, physical problems often come along with retirement. Auto Train, in particular, has a very high proportion of retirees. Most of them go to the dining car for meals, but there is always a significant number who have to be served at their seats in the coach section, or in their rooms in the sleepers.
That's a long way of saying the Auto Train onboard service staff has been serving passengers with these special needs for years, and you should have no trouble getting your needs met. You said "in our room", so I assume you're traveling in a sleeper. You will have an opportunity to talk with your car attendant when you board, or shortly thereafter. You didn't mention whether your husband has trouble negotiating stairs in the Auto Train's double-deck Superliner cars. This could be another factor. Ask your attendant how far away the diner is. It might be right next door, or it might be as many as four cars away. When you talk with your attendant, you can agree on a mutually acceptable time for your meals (both dinner and breakfast), time for the attendant to put down the beds, etc. Your attendant will also be providing similar services for other passengers in your car. Good communication and timely notification can help the attendant to serve everybody better.
On the Auto Train, it's not at all unusual. It's just another day at the office.
Tom