The Amperage limit is on your breakers, usually in the garage. You can't 'up the amperage' without doing some rewiring,
which you SHOULD NOT UNDER ANY CIRCUMSTANCES ATTEMPT
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.