I don't grow statice, but I know that sea lavender is a perennial statice that grows wild on the tidal flats on the NH and MA seacoast so should be hardy for you.

I found a link that says German statice is hardy to zone 4, so that also should be hardy. I don't know anything about this seed company, but garden watchdog might have some information.

Here is a link that might be useful: Limonium

I grew german statice,Limonium tataricum, in my nursery years ago. I wish I knew you then-nobody bought it although its really beautiful! It overwintered in pots in zone 6b above the ground. I think it should be used more in planters etc... It looks great throughout the season and is light and textural at the same time. In the ground, I had no problems in full sun to part shade. I would think it would not like wet soil but recently, I saw sea statice,Limonium latifolium,growing in a wet sand bog-albeit in sand at the edge-but still! Both Limoniums are incredibly drought tolerant.There are several other species,some crosses and named varieties that look interesting as well.You might want to look into some of the others for dried arrangements too. I was able to divide the German statice repeatedly. I think some lived in two gallon containers for around 8 years before they finally had it. Limonium sinuatum is sometimes found in annual packs in spring. I never had much luck getting it to flower in the ground but Im curious to see if it will do well in pots. Its perennial in mild climates and could join my family of "haulers" -or pots of "annuals"(tender perennials) that I haul into the basement every winter. Now that you have reminded me-I think Im going to search german statice out again-it would look great with the sedums that I have had living in some large planters for years-I think they could duke it out without a problem-and without any watering too!