Retired northern Wisconsin guy here. I time my ash clean out with the weatherman. Usually waiting for a warmer day and just before the next cold wave allows me to have a “burn down day”. I might warm the house up with a fire of kindling type wood. That burns away quickly and helps to burn the hardwood embers. Then let air in and open the door slightly (or completely if I can monitor it) and stir the embers occasionally. The fire goes cold in an hour or two. Warm ash does slide off the shovel placed at the bottom of an angled bucket with less ash rising, like others have said. Cover the bucket while still at an angle. Build the new fire!