I never heard of storing iris for the winter either . I'm zone 6. If you want the space for a rose I would transplant them now. Just make sure they are planted shallow. The rhizome likes to peak out of the ground.

I have no personal experience with this, but I did see some information on the Internet about storing the rhizomes. Since I have no personal experience, I hesitated. But The Google did have some information about it. It's possible there are some youtube videos about it as well. Good luck!

The only Google hits I get for storing Iris rhizomes are from gardeningknowhow and sfgate, both of which often give dodgy advice. I've certainly never heard of doing it. They only need dividing every three to five years although some old clumps can go on much longer. Since transplanting can affect flowering the following year I have no idea why anyone would advocate doing it annually. Why make work which is deleterious anyway? Can you link to your sources so we can see what they're saying?

I’ve never heard of anyone digging up a bearded iris for the winter. I live in Zone 3a with winter temps going to -40. My irises are thriving. Sounds like you need to make a choice ... irises or rose. (I would choose the irises ... way less work and potential issues.)

Here's a link to a youtube video from a vendor. Surely they have to store iris.

https://www.youtube.com/watch?v=a9scYOiWjFA

If you have a relatively short amount of time to store them, you could pot them up and store them in a coldframe or something.

"Surely they have to store iris."

Not really. There are many commercial iris vendors in this area, both beardeds as well as species, and none of them store iris outside of the ground. It is by far the easiest and safest way to hold iris. Also, storing iris rhizomes for any length of time will affect flowering. They are best planted or divided in late summer to early fall. Storing over winter and replanting in spring will preempt any flowering next spring.

I just came across this interesting article on storing iris rhizomes.
https://www.gardeningknowhow.com/ornamental/bulbs/iris/storing-iris-rhizomes.htm

I read that article. Note it comes from gardening know how, one of the sources I mentioned in my post above as being unreliable. And note that even that source doesn't imply storage is necessary only that people might sometimes want to do it. And Gardengal has also said what I did earlier. Lifting the rhizomes will inhibit blooming. If you need the space for a rose just move the iris to where you want them and leave them there.

If you want the rose instead of the Iris, I would pot them up and give them away like that.

Maybe you'll think of a place you want to move them to and be able to keep them since you liked them so much. I've kept some in pots for a year or more. They don't thrive, but they stay alive. Don't over water!

Now that flowering is over you can move or remove and discard them now, get your rose in the ground (if you have it at this time). If keeping any select a suitably sunny spot and leave them there, except for periodic lifting and division as a maintenance operation. It is time when you get a bunch of leafless rootstock growth in the center of the clump. The whole is lifted, the over the hill center sections discarded and the best pieces of the most vigorous outer ring of growth used to replant. With these divisions all oriented (facing or pointing) in the same general direction, rather than higgly piggly. Each piece used for replanting should consist of a fan and a single section of rootstock, with the fan ends all oriented away from the center of the grouping. Because it is the fan end that creeps across the ground.

Embothrium, thanks you so much for your explanation. Yes, I have my rose and I'll move into that spot. I also have a nice sunny spot for my iris's. Thanks so much for all your help!

Here is a pic of my iris. They grew about 30" tall. Does anyone know what kind they are? Thanks again.