The Back Sun Room- Keep it? Or Tear Down?

There is a back sun room that adjoins to the dining room which faces out to the back of the house. We haven't spent much time out there since it is a 3-season room and the weather just hasn't been warm enough. However, now that it is warming up I am starting to venture out to that room more often and am pondering what to do with the room. Honestly, since we need a new deck, what I really wanted to do was tear it down with the deck and re-build a smaller room with insulation so we could use it year round. Unfortunately, there are too many other things the house needs in terms of repairs so rebuilding that room is going to put put on the back burner for awhile.

Right now the room is home to my grandfather's dining room table that he built himself many many years ago. I am in the process of re-sanding and staining the table and since its a messy job, the back room was a good area for this project. Once that table is finished (my next home improvement priority!) i want to start working on the room. Honestly, its a bit of a mess, it is very old and not built very well, the walls have some holes and since the windows have only screens (the previous owners did not even have glass frames for the winter months), which has left the room in not the best condition. The walls definitely need a paint job and the tiles are very 80's. The easy fixes are paint and maybe a nice patio set. I definitely want to get glass window to help prevent rain from coming in through the screens and ruining anything I put out there. Some hanging plants also would help spruce it up a bit. Take a look at the pictures and let me know what you think. I know we definitely will put this room to use over the summer months!