Another pic...

It doesn't look so bad and is definitely savable. Cut off the black canes and from your pictures I think that will leave you with at least 3 good sized green ones.

Climbers take a lot of patience. It may be 3 to 5 years before it really starts to climb.

I think the black canes are from cold damage. It could have happened at the store or at your home. You mention 2 varieties so the 2nd one may have been more resistant to the cold or you got it later when temps were warmer.

Definitely cut them off, otherwise it seems to travel down the cane and make the entire cane go bad. Some say about 1" below the black part to where you have a healthy stem (inside the stem should look healthy also).

I had this happen this year, before knowing about the frost damage. My bare-root had about 6 canes coming out and I thought I had chosen such a good one, compared to the others that were in the store. But then I lost 4 of them before understanding what this is.

So I was down to 2 canes but like many plants, as long as the roots or crown are good, then your plant will return just fine -- in some cases, even better.

I also had another different variety already established in my yard, so while I had roses growing outdoors for many years, I had not experienced this kind of frost damage, so it was new to me. It could also be, as you said, one that is more established already.

cold damage or canker? either way, cut it down. when i was new to roses i thought cold damage was canker and fungicided after i pruned. turns out it was winter kill . because i cut back, they lived