Tried it, but it's too cold here! sorry!

I had to look this Trumpet Vine up on the web. Some sites say that it is half hardy whilst, interestingly, the sites that sell the plant don't mention this!
As you have the plants I would suggest that you plant them in containers (to prevent any rhisomes running round the garden) and make sure that they dont seed. You can then put the containers under cover for the winter.

What a great idea! Would aquatic planters do the job and allow the plant to breathe? Then you could have them submerged 'in' the garden but still look after them in winter if necessary...

I don't know what sort of root system they have, Karen, we don't grow them. The risk of aquatic planters would be if the Campsis has fine but fragile roots. These may find their way through the sides of the pot and then break off!!!!

Hmm, yes, something to bear in mind, I don't know either.

Campsis makes big plants (typically 30 feet) so are going to have a hefty root system. Any container would have to be a reasonable size or you'd end up with a permanently starved midget of a plant.

I've got this growing in two gardens - one's only been in 3 years, not doing too well because the summers have been pretty poor - it likes heat, so hot dry summers give good results, cool, sunless ones poor, so usually, the problem is getting the thing to grow properly, since they're also slightly tender. The other garden has a very old one in situ - it is vigorous, requiring cutting back hard, but I wouldn't say it's "horribly invasive" it certainly hasn't prevented surrounding plants from growing - on the other hand, I've never tried digging one out at the roots. I can't imagine its anywhere near as bad as Jasmine officinale, which isn't slightly tender like Campsis and spreads for miles, both through the soil and in length. Perhaps the people who find it impossible to eradicate don't live in a British climate - though I'm not sure I'd plant 3 of the things.