Husband and Wife Roommates?

Have been married for over 21 years with 2 children. The oldest is already in college and youngest graduates high school this year. Our life has/had really evolved into one centered on our children and as the youngest is about to leave the house that focus is going as well. For example our life just sucks to put it bluntly. Was pretty good for many years the real down turn probably occurred about 5 years ago when wife had hysterectomy. Since that time the frequency has fallen off and the quality well as said sucks. Think we still have maybe 1 or 2 times a month but more out of habit then acutal enjoyment. Would be even less but that about how often wife initiates and I just go through the motions as more of a duty then anything else. This past weekend wife made a joking comment about being roommates and thought heck maybe that would be better way for us to live then we do now. Looking for opinions on this were we stay together but I move into spare room and we just become roommates. Takes the pressure off both of us in regard to and we still are together for when kids come to visit and retirement. Its not that I want to go out with some other women just removing all the pressures and lets us reexamine our life with the kids leaving home.