Now for cooling, the montreal region has subzero temps from lateish november to somthing like almost april... Apparently Wikipedia has a half decent article. https://en.wikipedia.org/wiki/Temperature_in_Canada

Not sure about that freeze water in the winter and use it in the summer idea at such a low latitude...

But yes, using an artificial lake (or even a real one... given the population does not go bersek about protecting the wildlife) as a heat echanger might be an idea. Lake would most likely come close to freezing in the winter (need to engineer this properly) but in the summer you could get water from the depths to provide extra cooling power. Idea, put a beach there, get cheers from the population.

Other idea: run a river from up north in your datacenter and you've got a nice cooling strategy for basically... free. Better idea yet... Build the datacenter on top of the hydroelectric damn... Last thing to do is to run the lines... Not like Quebec had not mastered running lines over hundreds of kilometers anyways, they've been importing power from the north for decades.

Water is most dense around 4°C. Accordingly the bottom of a large body like the great lakes is near that temperature year round. This is part of the reason why fish can survive in lakes that freeze over in the winter.

This is exploited in deep water source cooling [1].

Such a thing is implemented in Lake Ontario since 2004.

Very cool imo :)

[1] https://en.m.wikipedia.org/wiki/Deep_water_source_cooling

I got an even better idea. Why not build the datacenter inside the hydroelectric dam? You get electricity from the turbines and cooling from the artificial lake at what's likely to be a high altitude. Now all you need it rock solid connectivity but you've got an incredibly small carbon footprint.

A lot factors go into picking data center locations, ambient temperature being one of them.

Other factors include network connectivity, risk of local government wanting to access data, price of electricity (you still have to power machines, even if you get cooling for free), labor cost to build/maintain the center, proximity to an airport, risks of natural disasters, etc.