thunder bay or duluth to st lawrence

[seadrift]

Three weeks is possible if you work at it. I made it from Ile Royale (Western L. Superior) to Thousand Islands (start of St Lawrence) in 2 1/2 weeks in July/August.
Two up (one slightly experienced, one inexperienced); two overnights and the rest long and short days, in a slowish 32’, mostly motor sailing in the light winds.

[Telmage]

Marina recommendation: Knife River Marina, Knife River, Minnesota. Great jump off place to start for St. Lawrence. Excellent haul in/out service. Our boat sits on a three axle trailer in which they haul us in and out each season.
Our boat (30' Morgan - weight on lift 13K without supplies). We have been at Knife River since 2000. In which we have sailed Lake Superior extensively. We started the Great Loop trip in Jun 2017 and end August 2019 at Knife River. Not sure if this will help, but I have reviewed our log book dated 27 June 2019 we left Buffalo, NY and arrived at Knife River Marina, Minnesota on 1 August 2019 with several extended day/night stays through the Erie, Heron, and Lake Superior (2 to 3 nights over). I have sailed the lower half of Lake Superior (US side) from Knife River to the Sault St. Marie in 13 days and few times. Over night stops only and weather was good with the exception of some rain and fog from Grand Marquis, MI to Grand Island, MI every time we have done this trip. If you haven't sailed Lake Superior you will needed to plan your weather closely over several days (NOAA, PredictWind, Windy/Windity, and SailGrib) for any Northeast-East-Southeast fronts. The Lake has tremendous fetch after a storm/front pulls through. We wait a day after front pulls through for lake is more laid down. Fair Winds...

[Mediaguy]

A few years ago We sailed (mostly motored) from Hamilton to Cheticamp Nova Scotia with only a few days off and it took us 5 weeks. If you really (delivery style) pushed it you could do it in 4 weeks. Based on that experience the distance you need to cover I don't think it is possible to do by a factor of 5 or 6.

Secondly the 13,000 is going to be cheaper than the expenses of moving the boat. (food for crew, fuel, dockage, and misc). We burned through almost that much in our trip.