Yes, definitely possible as others have said. My husband has periods of time where he's feeling better, more productive, able to go out and do some things he enjoys, etc... When he's going through a worse period and is mainly couch-bound it's hard to remember that those times can return, but so far they do. Sometimes not as good as he was, but his ups and downs seem to be cyclical, it's just that the cycle sometimes takes a long time to change so it's hard to remember that the present state isn't permanent.
I, myself, went from being completely couch-bound to the point where I would have starved to death if he hadn't been there to serve me meals, because I just couldn't even handle walking to the refrigerator and microwaving something. Now, I am fairly functional, I do dishes and laundry and grocery shopping and some cooking, I'm able to enjoy some things and work part-time from home. I still have ups and downs, but my baseline now is much higher than it was at one point. No matter how bleak it seems, things can change on a dime.
One thing that helps us is to always have something new to try - it feels like we aren't giving up. Most things are a bust, but a few things surprised us and have made a difference. For example, liposomal glutathione makes a noticeable improvement in how much activity my husband can tolerate without crashing. It's expensive, so he can't take it too often, but seeing that glutathione makes a difference for him, he's now taking a probiotic that produces glutathione endogenously. It's too soon to tell how effective it is (early signs are promising) but the fact that we have new things to try gives us hope that we can get better, even if not cured.
After being mostly couch-bound for about a year, he was able to take a 1200 mile mini-road trip for his birthday and had an amazing time. It required A LOT of overplanning and back up plans to account for potential health issues, but we made it happen and it was one of the best trips ever. I try to remember that when I get too focused on what we can't do (because there is plenty we can't do). I know 9 months of being house-bound is awful, but it's not necessarily your destiny forever. As hard as it is, I think it's helpful to focus on one day at a time, and try to find as much humor and joy in little things as possible until you are hopefully able to gradually do more.