Great to hear they are getting big already. I have been lucky enough to have this problem myself and posted a very similar question. The overall conscensus was leave the plants alone and just use a trenching technique (CLICK ON ATTATCHMENT FOR INSTRUCTIONS) when it's time to plant. The long length of tomato plant that is burried underground will actually turn into a large root system giving you strong plants. Good Luck

Here is a link that might be useful: Trenching Tomato Plants

The reason why they are gangly is because you planted them too early.
Inside, yes....plant tomatoes anywhere from late February to April---but outside---in Thunder Bay---what's that a zone 4--or is it 3.
The ground is far too cold yet to think tomatoes will grow as well as when the soil has firmly warmed up.
The sun at this time is not yet ready to support tomatoes...they love the sun...the warmer the better.
The sun has a way to go yet to warm up the soil.
Without the sun, the plants grow leggy and will produce, if you leave them, small lifeless plants.

Why not consider moving them to a container whose soil you can make a lot warmer--and use a lot of compost which they also like.

I'm taking you at your word...you plant tomatoes --as you do--every year---
Question: In the same place do you.

Tomatoes are far better given a different planting site every year--or at least every 2 years.
Rotating tomatoes is recommeded by those that grow them well.

Repot, repot repot I start several plants early knowing they might be overgrown but I repot them every second set of new leaves, burying them up to within 1/2 inch of the lowest leaves. These early plants are now in gallon pots and going great. All tomatoes are doing well and all have been repotted more than once. Now if only the weather would cooperate. Freeze tonight but everything tender is inside.