Oat seeds germinate in amazingly cold conditions. They're routinely used in site work to stablize soil and prevent erosion after late-fall and winter construction.

In the edible realm you could try arugula, mizuna, or any other of the fast-growing cruciferous greens.

Sorry to hear you have to move after all that work!

wheat

For zone 7 you should warm the ground early or keep it warm starting now.

If you warm the beds, your choices in plants expands substantially. You can start the seeds inside and transplant to insure germination instead of the wondering if you plant directly in the ground. The time spent waiting for the sprouts to pop up can have those beds toasty.

A cheap way to keep the soil warm is a PVC pipe, wood lathe, or wire frame with plastic sheeting over it to make a bed/row cover. It'll be lite enough to move around and store. Maybe even some kinda heater. The winter sun will provide a lot of warmth if you can hold the heat in.

The jury's still out as to using black or clear plastic for a soil warmer if you place the plastic in contact with the ground. My experience is black plastic warms soil better, but clear plastic bakes the weeds better.

You can grow the usual winter crops or even (if the beds are very sheltered) some summer types as well, like peppers, fast/dwarf tomatoes...choose determinate varieties, green onions, salad veggies, carrots, etc. heck, throw in some hardy flowers as well. Things that'll stand up to light frosts will thrive under row covers. Tender plants are not recommended unless very (very) sheltered. What you want is plants that are a bit tougher than most.

Here in CA they're selling violets, primroses, snapdragons, poppies (icelandic), and Kale for winter color that stands up to frosts...(nice that the ground never freezes...).

Hope this helps a bit.

In zone 7 you have plenty of time between spring and May to plant all sorts of things.

Any of the hardy greens, including lettuce, many of the Asians, rockett, chard, kale, collards and so forth, will mature by the time you have to move.

English peas should grow and produce full crops by then, too.

Some of the root crops, such as turnips and beets, will grow enough by May to indicate which of the beds worked best. You won't necessarily get full-sized roots, but they'll be big enough to compare growth habits. Besides which, baby beets and turnips are the best tasting ones anyway.

Radishes will fully mature in zone 7 by the end of May.

Some of the early Brassica varieties will grow enough to provide insights. Check the days-to-maturity on cabbages and broccoli, for instance.

In short, you have plenty of choices.

I agree with the above and would add spinach, turnip greens, green onions (started from sets for sure, not sure about seed). Look for shorter harvest dates...