A couple of places we use on Ishmael are under the dinette seats, behind the drawers. There's space there for me to store the sail repair kit and some other materials. It doesn't seem to interfere with the drawers function. I'm sure you also utilize the space behind the false drawer under the stove? We used to stow canned goods there. We also make use of the space under the pilots bunk, the after section, behind the battery storage. Finally, we also kept some stuff under the floor board between the head and hanging locker. These need to be waterproof things, because in blue water we'd get some water over the bow down the chain line into the anchor line locker, and that drains to the bilge under the floor.
Be careful about weight. We were shocked the first time we stowed up for a long open water cruise. Despite how heavy the GD is, the added weight really put her down in the water and we lost at least 1.5 knots speed. I think our issue was ample fresh water and that is heavy stuff.