I doubt you'd be able to bring them back inside for 10 days and then put them back out for good. I think you'll have to restart the process. Not sure about the huckleberry, but every kind of pepper needs consistent warm conditions, which we will not have until June. I'd fear you'd lose those seedlings altogether if you leave them out, even under row cover. Being ready to transplant depends on the plant and the time of the season and if you've hardened off enough. Fedco seeds has a good planting guide for central Maine (link below), but experience is the best guide. I use the general rule that warm weather loving plants like tomatoes, peppers, melons, cucumbers, etc are best transplanted in June and covered most nights, even through the summer. And even then we can only hope for less cold rain and more warm sun!

Here is a link that might be useful: Fedco Seeds Planting Guide

very grateful for the info.i'll be cont. planting my peppers, as i just learned (yeah gardenweb) that theyre perennials. that way I could overwinter them and not have to do this again next year. i was thrilled w/the warm weather today. the huckleberries (only) went out all day. from 9 - 7. i watched them very closely the first few hrs as it was chilly, but they did fine. quite a breeze today too... i wonder how hearty they're supposed to be??