If it was me, I would plant them.

I planted iris last week that came from a sale. I do not know if they will have time to establish well enough before the first frost, but I am taking the chance. They are replaceable if I lose them. If I do not plant them then I definately will not see bloom next Spring or perhaps the Spring that follows that. This is just an opinion. Also, since there are no atmospheric or zonal adaptations that yours would have to go through,
they will likely recover as quickly as possible.
K

PLANT THEM! They will do fine. I am still waiting for an order from Brecks to get here. GRrrrrrr! I have moved some of mine and they are only days in the ground and are growing good.

Here is a link that might be useful: Iris

if the ground freezes ... after it is frozen.. you might want to throw on some mulch.. to avoid heave ...

they can handle winter.. i dont think they belong in the warm house ...

the issue in my z5 .. is sunshine on soil.. thawing the top few inches.. and then they heave out of the ground .... the mulch would temper such ... not allowing the ground to thaw ...

as with all plants in winter.. get them dormant.. KEEP them dormant .... all winter long ... and you will win ...

ken

Thanks everyone.