Move it now. Cut it back severely and get as many roots as you can. It may be short for now but once the roots begin to grow again it will recover quickly. The existing roots will only support a like amount of top growth. No matter how hard you try most roots, which are composed of many almost invisible feeder roots, will remain in the ground. The best time is in spring just before it comes out of dormancy. Mix generous amounts of horse manure, compost, or other organics in the planting hole when you plant it.
These will break down slowly and supply nutrients as the roots grow into them.
And yes you can plant in the same place another rose was planted.

Early spring, as the buds on the canes are swelling or have just broken open with first leaves expanding is a very good time to move it.

Maiden's Blush is an Alba rose (& one of the best of that class!!!), so don't be shy about asking questions about it over on the Antique Rose forum. It's very famous (& LOVELY, and it SMELLS SO GOOD!!!)

Follow all karl's advice and especially try to get as many of its roots as you can. It won't require daily watering after you've moved it, but you'll want to pay close attention to the soil once you've moved it and watered it in. You should probably put some sort of mulch of plant material over it after you've watered it in. That will help a lot with keeping the soil moist, and it will need to stay that way until the rose is well established in its new spot. Any chopped up plant material except peat moss will probably do the job. Don't apply it right up to the cane bases. Leave those free of mulch out for an inch or two. After that lay down an inch or two of mulch. (At Hershey Amusement Park in Hershey, PA they use the empty hulls of cocoa beans as the mulch around their plantings, including their roses.)

Wow - looks like I guessed right on this! I'll see if I can move it within the next week.

What do I need to do for it if the temps dip again? So far we're staying above freezing and one would hope we won't drop down again but this year has been so weird that I won't make any weather assumptions (I'm in MD, btw). If it turns cold, any action I should take?

And york rose, I can only agree with you - I LOVE this plant. It was the first rose bush I bought (on a whim), I was convinced I had killed it and yet after I got it in the ground last year it put out bloom after sweet bloom. It's just a beautiful thing. And thus why I want to move it to where it can stay for good.... without killing it in the process!! As I recall Albas don't like to be crowded (it really REALLY hated being in a pot), but I hope they don't mind being disturbed. Hopefully this will be its final home and it can live well and prosper!

Thanks for the advice - appreciated :)

Go ask your question on the Antique Rose forum. I suspect the answer is going to be some version of "cover it in a blanket", but I don't know for certain, and that forum has far more experienced rose growers than me on it!

Are you really expecting it to get cold again? I honestly didn't think zone 7 Maryland *ever* got what either I or an alba would consider cold. If you are expecting single digits, I'd wait until it warmed up again. Otherwise, I'd give serious thought to the fundamental differences between roses and tender annuals, and remember which it is you are dealing with.

Years ago, we had a keeshond visiting for Christmas. It was about zero several times when we took him out, and it was the job from *$#&**&(# trying to get him back inside. The humans were frozen. The dog had snuggled into a nice snowbank, and thought we should all stay out in the wonderful weather.

Mad Gallica, that's why I asked - I'm not experienced enough to know what roses consider "too cold"! (For the record, this past winter went below freezing at Thanksgiving and didn't pop up above too often until a week ago - it's been ~15-28 degrees for nearly 3 months which I think counts as "cold", especially in an area which usually hangs in the high 30s and upward.)

Last question (for now): do I cut it back before or after I move it?

Thanks again!

If you cut it before you'll probably have an easier time moving it, for there will (obviously) be less to move. I grew Maiden's Blush quite successfully when I lived in the Philadelphia area. It's a bit warmer around DC, but I suspect it's still cold enough there for Albas.