If you don't get a response here, the Perennials Forum may get you an answer.

I've only grown native Wild Blue Lupines, but they are frost hardy when grown outside. And I've only had to adjust seedlings from indoor climate to sunny, hot outdoor weather. I think they would do OK, though I might cover them at night to minimize the dramatic temperature shifts.

Martha

Thank you guys. I went ahead and planted one of the plants (I have quite a few) and it's still kicking even after a frosty night. I'll see how that one does for a few days

Lupins are not frost tender but they do need hardening off before they are planted outside.

I planted a lupine seedling (Russell Hybrids Mix) in early spring last year - my notes say on 4/12. I did cover it once or twice with an upturned clay flower pot for an overnight snow or frost forecast; not sure if that was necessary or not. It was just fine.