Most hydrangeas will be happy in a part shade/part sun situation, especially if the sun is early in the day. A northeastern corner sounds pretty ideal!

As to sizes, there are some more compact, smaller growing varieties you could consider. 5-6' or more is pretty standard for most macrophyllas but the Cityline series produces quite small plants, 'Pia' (aka 'Pink Elf) is considered a dwarf form, seldom exceeding 3' and there are several selections of oakleaf hydrangea that will stay about that size.

How well a hydrangea will hold up to rain kinda depends on the type. The larger mopheads can become pretty laden with rainwater and will often droop -- lacecaps much less so. Developing a strong woody framework for the shrub will reduce this tendency. IME, those hydrangeas that bloom on new growth - Annabelles and paniculatas - have a greater tendency to flop with rain simply because the growth that generates the flowers is not ripe or strong enough yet to support them. Rather than pruning back to the ground each season, allow some of the stems to remain in place to ripen and become more woody, hence more supportive.

Gardengal to my rescue again.
Thanks so much for taking the time to help me.
I'm going to look for the City line series at my local nursery.

Gardengal,
I was doing some Googling and came across a hydrangea called "Little Limb" and wondered what you thought of this one? I love the lime color and it would look awesome in front of my house just below the dark shutters on my window.

I meant to say 'Little Lime' not Little Limb"

I don't have any personal firsthand experience with it but it seems to be just a scaled down version of H. paniculata 'Limelight', which is an extremely popular selection. Paniculatas will take more sun than some other hydrangeas but they do produce big, fat flowerheads than get weighted down with rain. And the lime color is unlikely to persist throughout the season. The blooms start out quite green but eventually turn a creamy white before fading to pink.

Gardengal, thank you. It sounds really pretty. I called the garden centre where I shop and they don't carry it but would see if they could get it in for me. They do however carry the Cityline series, so that is good news. I appreciate all your help.