Kleo that's what I do. I dry excess Morel/Oysters, then double bag and freeze them. They rehydrate surprisingly well when used for sauteed on steak, or for soup. Give them one to several hours in water or broth to rehydrate. 20-30lb fresh then dried, easily gets me through the year.
I am usually able to air dry them on window screens, but this year, with all the humidity, after 5 days they still contain moisture, I need to pick up a food dehydrator.
Another good way is Saute them in lots of butter, add salt, garlic or whatever you do, then pour into small narrow mouth containers and freeze, making sure mushrooms frozen are under the butter.