Jan, my
experience with seedlings has been they are very strong out of the seed, but then they start to suffer and sometimes cannot recover well. I would do the buckets, drilled in the bottom for drainage, with a 50/50 mix of your soil and sand, planted closely, kept from freezing but allowed to have sun and watered with compost tea or 50% diluted
pee, unless that creeps you out. But it's free and will give them some nutrition. Those are not too hard to move.
It's spring now so everything wants to be planted yesterday once the freezing stops. Once you get moved, try to prepare 1 gallon pots to transplant into, then you can take a breather for a few weeks, let them get a nice rootball before transplanting.
Try to prepare the soil where you are moving to by mounding Very Big Piles of organic matter over the top.
But if you've got the
energy and some stolen time to give some attention to these seedlings, you'll be a year or two ahead of letting it slide. You'll be glad a year or two down the road that your fruit is underway. I've never thought afterwards, gee, I wish I hadn't protected and transplanted those seedlings.
In fact, today I discovered some 2011 tomato seeds ALL germinated! I couldn't believe it. I thought maybe 25% if I was lucky. Now 90% of them need transplanting! But come July I will be very glad!
An important distinction: Permaculture is not the same kind of gardening as organic gardening.
Mediterranean climate hugel trenches, fabuluous clay soil high in nutrients, self-watering containers with hugel layers, keyhole composting with low hugel raised beds, thick Back to Eden Wood chips mulch (distinguished from Bark chips), using as many native plants as possible....all drought tolerant.