Lavender Dream?

I only see one rose.

It reminds me of 'Dortmund' (link below):

Here is a link that might be useful: Dortmund

Could be 'American Pillar'

I agree with collinw that the pink one (only photo I can see) looks a lot like American Pillar. Is the plant a large, once-blooming rambler?

Yes, it does look like 'American Pillar'.

I previously guessed Dortmund, which is a repeat-bloomer.

However, if it only has one big bloom cycle a year in late spring I agree with the others that it could be American Pillar. I have seen that variety growing in the south of England (link below; click on "photos" tab for more pictures):

Here is a link that might be useful: American Pillar