Most of our paddling will be on Lake Huron (slightly intimidated so definitely only when it is calm and staying close to shore ... just pleasure paddling for an hour or two at a time, no gear), would manage one backcountry 4-5 day flat lake camping/ portaging paddle a year (with camping gear).
As to using bigger canoes on bigger water, that is a reasonable generalization. But one must also factor in cost, weight and how many canoes one has in a fleet. Not everyone has an armada.
And also, Lake Huron is not everywhere
LAKE Huron.
I once drove along the entire south coast of Lake Superior with my fragile Hawaiian outrigger solo canoe and never once put in. Too scared stiff. Everywhere, it looked like an angry, storm-tossed Arctic Ocean.
But then I drove over the top of Lake Huron into Georgian Bay. I spent about five days paddling around the northern and eastern shores of Georgian Bay and it quickly became one of my favorite all-time paddling places. I don't think I was ever more than 500 yards/meters from land, because there are thousands upon thousands of islands and fractal coastline. That's where I carefully stayed and was never in danger of big water waves.
I still think a 16' (minimum) to 17½' canoe would be satisfactory for such relatively sheltered Huron waters and rivers.
I also wanted to throw 3 canoes at you that I have found for sale. All 16' Kevlar ...
I'd rule out the Sawyer 190 Cruiser. To me, it's too short (15-9), too narrow a waterline (30.5), and too shallow (12.5). Some solo canoes have specs like that.
Scott Canoe went out of business in 2013 and Abitibi bought its molds and is now producing Scott's former hulls. You say you like the Scott Prospector. Here is its manufacturer's description and specs:
Scott Prospector
Manufacturer's Description:
The Prospector 16 is the first choice of experienced wilderness paddlers. It is ideally suited for rough waters and large loads. The Prospector 16 excels at quick manoeuvrability. Its easy ride is ideal for novice and experienced paddlers alike. A true expedition canoe handling all you will find in the deep wilderness.
Specifications:
Length: 16'-0"
Width: 36"
Centre Depth: 14"
Bow / Stern Height: 21"
Weight: 67 lb. (Fiberglass)
Weight: 56 lb. (Kevlar)
Weight: 49 lb. (Exp. Kevlar)
Weight: 44 lb. (Ultralite)
Capacity: 940 lb.
The ad picture you show is of the Scott River Dancer. Here is its description and specs:
Scott River Dancer
Manufacturer's Description:
An exceptional well balanced craft, ready to carry you wherever the adventure leads. An ideal canoe for rivers and exposed lakes. The V hull design makes this craft firm tracking and solidly stable. It sheds waves for a dry ride when you need it and is easily handled, granting you the confidence to make the River Dancer your go-anywhere choice
Specifications:
Length: 16'-0"
Width: 36"
Centre Depth: 14"
Bow / Stern Height: 23"
Weight: 67 lb. (Fiberglass)
Weight: 56 lb. (Kevlar)
Weight: 49 lb. (Exp. Kevlar)
Weight: 44 lb. (Ultralite)
Capacity: 940 lb.
Not much spec difference except for the greater bow/stern height on the River Dancer and the mention of a V bottom on the River Dancer. Rocker isn't mentioned for either.
I think the River Dancer would meet your needs just fine. If it's the 56 lb. Kevlar layup, that is a heavy Kevlar layup. Probably mostly fiberglass with one Kevlar layer. That kind of layup is pretty bombproof and I wouldn't hesitate to take it down easy whitewater or be afraid of scraping or bouncing off some rocks.
The pictures of the Abitibi canoe don't say what Scott model it is. Here is the current Abitibi canoe lineup:
abitibi&co
abitibico.ca
From the all-yellow fabric color, this could be an all-Kevlar layup, which should be much lighter than the 56 lb. Scott River Dancer. Just from the photo, it looks like it could be the right size canoe for you. I would encourage you to contact the seller to get the name of the Abitibi canoe model and as many of the specs, including weight, that you can.
That's my research and take . . . so far. Buying a canoe is a "trip" unto itself.