The Amperage limit is on your breakers, usually in the garage.  You can't 'up the amperage' without doing some rewiring,

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I put the super-bold warning in, because it sounds like maybe you don't have much experience with power work.  Apologies if I misunderstood.

Anyhoo, as you say a good solution might be to run one of your mining rigs elsewhere, like in the garage or another room.