While it may not be possible for a house to be too well decorated, it can certainly be too full of stuff even if it is excellent stuff. When preparing to sell your home, the standard rule is less is more. It's important to make your home look as spacious as possible. Minimal furniture and knick-knacks on tables make rooms look bigger and more neutral. An overabundance of antiques, art and various collections can not only make your home seem crowded, but can lead the prospective buyer's eye away from appealing features, such as hardwood floors, crown molding, etc.
Mirrors can replace artwork on walls to make small spaces look bigger.
You're going to have to pack up and move anyway. In the meantime, you'll open up your home to the imagination of prospective buyers who will have the room to envision their own treasures in the space. In the dining room, remove leaves from the dining table and leave only a few dining room chairs. Don't let your furniture suffer from the heat. The hot, dry weather can take its toll on fine wood.