Answer: In my experience the two hydrangeas you mentioned are not considered fragrant, however some of the other types of hydrangeas are. For fragrance you might look at Hydrangea anomala petiolaris (climbing hydrangea, slightly fragrant) and also some cultivars of Hydrangea paniculata. Fragrance is always a bit subjective so if possible it is better to smell the plant yourself and see if you like it, or not.
The patio hibiscus (Hibiscus rosa sinensis) is not winter hardy in Wisconsin so you would have to bring it indoors as a houseplant each fall or replace it each year. It can be grown outdoors year round only in very warm climates such as southern Florida.
There is a hardy shrub hibiscus called Hibiscus syriacus. This shrub needs full sun and a well drained soil and blooms during the summer. Perhaps you would like one of those. Your local professional nursery staff should be able to show you some.
I hope this helps.
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