Well, it's pretty simple. Peppers are intolerant of a freeze. So you look up the average date of last frost for your locale, add a couple of weeks to it, and chances are you're good to go. If there is an unusual freeze after that date, you need to anticipate it and protect the peppers.

Low, but non-freezing temps won't hurt them, though they won't do any growing during those.

I wouldn't. Even in my zone I don't plant peppers out until mid-May as they prefer much warmer soil temps than tomatoes. It is far too easy to end up with stunted growth, lower yields, and BER - a common results often discussed on the Peppers forum.

Even then I always check the actual soil temps before transplanting them and make sure it is at least 65 degrees. Sometimes that means waiting and transplanting them into larger containers indoors to tide them over.

Dave

If you're going to try now, I would use black plastic to make sure the soil temp stays up, and consider water walls to make mini greenhouses for them. If not, I would just put in larger pots. I don't plant my peppers until May, even with water walls.