How large a pot?? You need something the size of a wine barrel, at minimum, to keep even a modest sized climber. These are large roses that need a large root space.

That said, you could get away with a miniature climber more easily. However, the climbing miniatures I know are all colored, not white.

You could grow Darlow's Enigma in a large pot for a few years, but long term sustainability would be the issue.

Thanks Paul. I haven’t bought the pot yet but am planning on something like a wine barrel or larger. Could you give an example of a miniature climber? That’s not a term I’ve heard. I’ll look into Darlow’s Enigma! Much appreciated!

Anyone growing SOMBREUIL?

No, and NOOOO!!!!

I'm not entirely sure which answer applies to Darlow's Engima, and which to the rose commonly known as Sombreuil. Sombreuil is too large (and blackspotty, IME) and Darlow's Enigma, is a thorny, tangled mess that escaped from Sleeping Beauty's castle.*

What I think you are looking for is a rose with somewhat long canes that isn't usually considered a climber. Something like a white version of Lafter.

*disclaimer: I spent much of yesterday afternoon giving blood, aka pruning Darlows Enigma.