If your pots are large enough I think they should be ok where they are. You just want to be sure they drain alright if you get a ton of rain. I have two in an absolutely giant pot, that I planted last fall. I left it outside over the winter here and it was fine. They are taking off like crazy right now.

Don't worry that yours are not taking off now, they are probably growing roots and establishing themselves. It usually takes a year or two for them to settle in.

I live just a bit further north from you in a similar climate and I grow a number of clems in containers (and a whole bunch of other stuff). All remain outdoors, exposed to the elements, all winter without issue. The same conditions for a fast draining potting medium that is a requirement for container culture during the growing season is just as important in our winter rainy season. And just because our rain tends to fall mostly in winter, it does not necessarily mean that it is always sufficient to keep permanent container plantings happy during this period. I have actually lost plants over winter from lack of water simply because I assumed they were getting more than enough rainfall. It ain't necessarily so :-))