Was married for 20 years ,seperated now. Left a year ago.husband wants to sale house, i don't?

I left my husband of 20 years last November. When I left I left the house and everything , we still communicate and are on friendly terms. The problem is the house. My parents gave us the land and we put a double wiide on it with a full foundation.Plus my parents land joins ours and they don't want new neighbors. Well he wants to sale it and I really don't want to. First of all my parenst don't want me to and second , the guy I'm dating now is in poor health and one day I may need to have the house back. I don't have the option to buy it right now. I want him to rent it out and me and my Dad will take care of any maintain or complaints. My ex says no he just wants to sale it. How long can I hold out on him? We are not divorced yet and neither one of us has filed. Help???