You do realise that power draw likely averages less than 350 watts. Your A/C running for an additional hour or two a few days a month would cost you a dollar or two, max.
Given that the load is likely removing peak daytime heat, then sustaining a less-challenging night-time temperature, the net impact is probably even less.
Given that the load is likely removing peak daytime heat, then sustaining a less-challenging night-time temperature, the net impact is probably even less.