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Is this a long term thing? If so then I'd look at putting in floor vents (cellar ceiling) as you'll be able to use some of the heat to warm up your house, reducing heating costs!
No point throwing heat away!
On that thought, big fan drawing cold external air into the cellar, vents (or vents with fans in) exhausting that air into the house. Assuming the air gets warm enough of course. It should do, given that most of the power going in comes out as heat. The ideal would be to have the whole house as a closed loop, feeding the air from the house back in to the cellar to be re-heated. The only issue is that the gpu's (and the house!) would probably get way too hot!