The Illecilliwaet Neve in Rogers pass on the Asulkan valley side has snow all summer long however it is pretty flat. The Uto Glacier is another option or the Hermitt Tupper area on the north side of Highway #1 is snow covered for a good portion of the spring and summer with a glacier up there as well. You could always hit up a portion of the Wapta Traverse or head to the glaciers around nelson like Kokanee Glacier or Woodbury Glacier.
August should be easy for you it is Sept where the skiing will be rough on those sun cups and runnels.