Probably getting tired of this topic, but for a game that makes you craft most of your items, having a tiny inventory makes no sense. A bigger inventory would only help so much. I think that having a massive storage with the shop keeper would be the most useful thing. Instead of just telling you to buy something the shop keeper would have an option to open up a storage room where you could unload all your items.
The pocket dimension coming in the next expansion will effectively do what you say except you can access it from anywhere and anytime.
