Hi 'Green Gardener', It's not silly to want to save a plant. Someone asked the same question in the Hydrangea Forum and despite that gardener being in zone 6, the answer is close enough to your zone to be applicable. You didn't mention how tall the plant is now, but try the link below and see if it helps. Good luck - they're nice plants to have.
http://forums.gardenweb.com/discussions/2000397/climbing-hydrangea-transplant?n=2

You can also grow it as a groundcover or transplant it to near a tree to climb up - there's an old thread on the Hydrangeas Forum with much information.
Climbing Hydrangea - Lots of??

The idea of a groundcover is very appealing.

Claire

A quote from gardengal48 on that thread :
"The species Hydrangea anomala is a climbing form of hydrangea, as are all
of its subspecies. There is not a "shrub form" per se - it and any of
the subspecies can be grown as a shrubby groundcover simply by letting
them cascade over themselves rather than training them up a support."

Claire

Oh look at that. I was so excited that I landed in a New England forum that I didn't even look for a hydrangea forum. Thank you for answers.

My concern isn't so much where to put it after I have to remove it. It's more of a "am I going to kill it when I have to take it off the house". I'll poke around in the hydrangea forum. Thank you again for pointing me in a new direction.

The impression I get is that this is a very very tough plant and you really have to work hard to kill it. It just will take a very very long time to get re-established whatever you do with it. I have one growing on a pitch pine but it doesn't climb too high, I think because the squirrels keep knocking it down.

C_Coy, You are always welcome here. It's often useful to get input from local gardeners, and this forum is usually one of the busier ones, though there is a good amount of traffic on the hydrangea forum as well.

Climbing hydrangeas want to be really large plants, but I know there was someone who used to post here who pruned hers to climb a large strong trellis. Mine grows up a concrete retaining wall. I have a friend who prunes hers to climb a large old dry stone wall that runs along her road frontage, and it is commonly grown like Claire's, up the trunk of a large tree. Do you have somewhere else to plant one if you decide you don't want to maintain it where it is? IME, many hydrangeas are relatively easy to root from cuttings, so you could start a cutting and when the cutting is well-rooted, plant it elsewhere. When it comes time to redo the house, hard prune your current plant (or you could start the process now) and then maintain it through pruning to the size and shape you want. Since it by now has a great root system, I think it will probably come back fine, though I am not sure of that.

Thanks, everyone, for your answers this is all very helpful.

I don't mind it where it is, personally, I think it looks amazing attached to the garage and it seems pretty happy in the environment where it is.

Cuttings. That sounds so advanced to this absentminded gardener. Kind of like when my mom feels overwhelmed when asking me how to use the computer. I want to do it but feel like I would somehow do it very wrong and wreck havoc on the natural world. Which is utter silliness but that's well above my put-it-in-the-ground-and-hope-it-grows methodology.

Oh, that sounds perfect!