In zone 3 I am not sure there are any of the double, large-flowered types like Josephine that are hardy, and even in my zone the early-flowered types usually don't have buds overwinter successfully. So even the doubles in warmer climates bloom a bit later due to needing to grow more flower buds and as singles since for many doubles, only the buds overwintered from the previous year are double.

I went to the Clematis on the Web search page and plugged in zone 3, and although their database doesn't have complete hardiness info on all plants, I still got a good list of zone 3 hardy clematis. You may find some of them in nurseries, but since I don't know where you are, I don't have any nurseries to suggest to you; many nurseries don't ship between countries. If you use online nurseries, you can see if they have a zone search function and use that to see if any clematis show up.

If you want to add your location to your name so that we don't have to ask, you can go to Your Houzz in the upper right of every page, click Edit Profile, and you can add location to the blank for name publicly displayed or else on the left side click advanced settings and add it to the line with zone info.

I am a bit confused . . . this must not for your zone 6 house?

Since you are in Canada, many posters have mentioned that they have found various clematis at Canadian Tire, but you'd need to check hardiness before buying (I use the browser on my phone to check.) Clearview Horticultural is in BC I think, though I don't know if any of the clematis on their list are hardy enough for your needs. They sometimes have 'Joe Zary' which is hardy to zone 3 and is quite double, though not as large as Josephine and a different shape.