Dude. Wow. If you made it any bigger you'd have to terrace it. I'm thinking you might have problems managing anything on top of it without compacting the soil.
That said, why wait till spring? Come August, you could be planting peas, carrots/onions/garlic (not near the peas, and those mature next spring), lettuce, cruciferous vegetables (cabbage, kale, brussels sprouts, broccoli etc), and/or winter squash.
A good seed selection