When choosing a climbing rose for a Toronto garden, I usually start with where the rose will be planted and how many hours of sunlight exposure it will get. You included this information, which was helpful.
Roses need at least 6 hours of direct sunlight per day to thrive in Toronto. Although you mentioned planting them on the north side of the fence, which typically casts a shadow on the plants for many hours in Toronto, it sounds like they will be getting 6-8 hours of summer sunlight along your fence line.
The next thing I think about is how high is the fence? If your fence is 5-6 ft tall and you would like the roses to grow to the top of the fence, you don’t necessarily have to get climbing roses. Many of the taller rose species can also be trained to grow up a fence 6 ft high and beyond. Some shrub roses can reach 6ft-10ft. You can prune them to keep them close to the fence, or choose varieties that don’t grow very wide.
Since Toronto can experience very cold winters, and humid summers with periods of high heat, it is worth looking at roses that have been bred in Canada for these conditions. The Explorer Series is a good example. There are repeat bloomers in this series in a variety of colours, and that grow tall enough to cover a fence.
Here are some that may be of interest to you:
Canadian Explorer ‘Alexander Mackenzie’ red, 5’6 ft tall,
Canadian Explorer ‘Martin Frobisher’, shrub rose of rugosa parentage, soft pink, continuous flowering, 5-6 ft high
Canadian Explorer ‘Captain Samuel Holland’ deep fuchsia pink 6-10ft tall
Canadian Explorer‘Henry Kelsey’ Climbing Rose 6-9 ft , spicy fragrance, red flowers with attractive orange/yellow stamens when bud fully opens
Canadian Explorer ‘John Cabot’ Climbing Rose, deep fuchsia pink to red, 8-10ft
Canadian Explorer ‘John Davis’ Climbing Rose, pink with yellow tones, continuous flowering spicy fragrance, 6-8ft tall
Canadian Explorer ‘Quadra’ dark red fragrant flower, shrub rose/ climber 5-6 ft, recurrent bloom
Canadian Explorer ‘William Baffin’ Climbing Rose, 5-9 ft, continuous bloomer dark pink to red
I have added a link for more information on these Canadian Explorer roses. Go to Canadian Roses and follow the drop down menu to Explorer Roses.
There are other popular climbing roses which require some extra care to get them through winter- such as Eden Climber Rose (aka Pierre de Ronsard). Very popular in Toronto with its beautiful cupped soft pink to cream blooms. These were bred in France, but propagated in Ontario. They are grafted onto multiflora stock. When planted in a sunny spot, they can do well in Toronto gardens- but the canes are not reliably hardy over winter. This can mean some fairly extensive die back over winter if the plants aren’t protected/winterized.
If you love a particular rose, check to see if it is propagated in Canada and whether it is grafted. It is safer to winterize your roses if they are grafted specimens to protect them from winter damage or death.
Ultimately, the type of rose you choose will depend on how much time you have to care for it. The Canadian Explorer roses are generally more disease resistant, and very cold hardy- which means less winter preparation, less pruning off dead branches in spring and treating diseases in summer.
If you enjoy spending time with your plants, and have time to monitor them throughout the growing season, you can try other roses originating from around the world but propagated in Ontario for your best chance of success. Look for disease resistant varieties. Some examples would be the fragrant, soft pink, old fashioned French Bourbon rose ‘Souvenir de la Malmaison Climber’/ the unusual mauve, repeat blooming climber ‘Stormy Weather‘/ ‘Claire Austin‘- named by David Austin for his daughter. A lovely fragrant creamy white climbing rose/ and ‘Galway Bay’ a vigorous coral coloured climber. All grow in Zone 5 and will benefit from winterization, in the event that temperatures dip below -20 celsius.
It is too late in the season for planting bare rooted roses, and difficult to find any. Potted roses are in abundance at garden centres currently and ready to be planted now. Good luck with choosing your roses!