Leaving the plants in pots over the winter ?

I'm going to WS a bunch of Echinaceas today. I have 7 varieties.

currently, i do not know exactly where they will go... so i was thinking i could leave them in pots over the winter, then plant them Spring of 2012 when I know where they will go, and I can figure how tall they are going to get.

is that possible? do I need to protect them? they will be in Zone5, and i can leave them in my unheated sun room... they'd be protected from the elements, but not the cold.

any pointers....

Oh here is what i have...

Bravado
Coral Reef
Merlot
Mac N cheese
Sunrise
Summer Sky
Tennesseensis

I assume most are Hybrids, so i can't expect them to look like the images i find, right??

Thanks in advance,

Terese

I would guess that you can leave them in pots over next winter. I've seen some Echinacea plants in pots sold up North in the early spring that were plants from the previous year with new growth appearing. My guess is it would be alright to leave them outside during the winter so that they still get moisture from rain/snow. The moisture and snow cover act as insulators. The concern with the sun room would be if the plants are allowed to dry out and are exposed to real cold temps. Dry/unprotected and very cold is generally not a good combination.

I believe Bravado and Tennesseensis are the only seed grown ones that will come true to form. The others will most likely be different from the original hybrid.

Thanks.... maybe I'll try to find an area, where they can get the snow/precipitation, yet try to more protect their roots.