Great stuff! Season extension is such clutch infrastructure to have and I'm glad it's paying off for you already! Keep in mind that nurseries in your area might be updating their greenhouse poly and their offcuts are an inexpensive way to increase the area you've got under cover (and a good way to reduce the footprint of your expansion).
We planted a bunch of garlic and perennial onions last fall, and have maybe thirty pounds of potatoes to plant once the soil becomes workable. Saved seeds from our tomatoes last year, so a mix of six varieties to work with. Planning to do much more winter squash and pumpkin this year, as well as diversifying our annual greens like lettuces and spinach. Hundreds, possibly thousands of perennial seeds have been stratifying in containers and air prune boxes over winter, and there are a few hundred cuttings and seedlings from last year that are heeled in and waiting to be potted or transplanted in another month or two.