With enough space, it would be nice to have a workshop like Norm Abram does.
However, I guess I am getting old and tired, and do not want to set up something like that anymore. What do I build all day with such a facility? My electronic projects, my cooking experiments, and a bit of gardening take up all my time. And there's dirt bike riding and RV treks. Different activities for different people of course.
Anyway, back on the OP's idea of upgrading the home in retirement, I used to entertain the idea of relocating to the Puget Sound, preferably on Bainbridge with a waterfront lot with a view of the Seattle skyline. Yes, it would be a major upgrade even if the new home were the same size or even smaller, as it would take selling both of my homes plus some additional cash to get a home on a lot with the above features.
I have given up the above idea though. Too old and tired to move, plus we both have a lot of family roots here. We are both close to our siblings and extended families, and would be lonely out of state. And with my homes only 2-1/2 hr drive apart with entirely different climates, I slowly realize that the grass is not really greener elsewhere.
Note: no grass with either home, with xeriscape in one and natural high-country evergreen landscape with the other.