Roses need help to climb.
I planted a Gertrude Jeykll & a few others last autumn & am training it onto a trellis. I'm having a go at the fan type method where you tie stems as horizontally as you can so lots of flowering side shoots come off those main lateral stems.
I'm still learning it as I go along, so I'm sure someone can explain it better.
You do need either a post or pillar you can cross the stems around, or if on a fence either trellis or wires to tie the rose stems in to, however you want to do it.
David Austin do say that one is good as a short climber, & certainly the stems on mine are very thin & floppy at the moment, it is very young though. My experience with the ones they call arching growth, is that it takes about 5 years for the stems to support the weight of the lovely big blooms, without flopping the stems out wide, unless I supported them in some way.
So I'd consider if you have room for it to be a rather large arching shrub if you decide against it as a climber.