The advice of not planting impatiens was that if the previous years planting became infected (with downy mildew), additional plantings would be infected. You won't have much success keeping the hanging basket indoors - it will decline over time because of conditions. It may or may not be one of the new resistant types (Bounce, Big Bounce). If not, you still have a good chance they won't be infected because it is a hanging basket and not being planted directly in the ground. Just watch it through the season - if it develops white fuzzy growth on the undersides of the leaves and drops the foliage, discard it.