Our house doesn't have a bathroom on the main level, only in the basement and the second level. Both flights of stairs are 15 steep steps. I'm worried that even after she's trained, it's going to be difficult to get upstairs in time after she says that she needs to go. Anyone have experience with this? Should I have a potty chair for the main floor as a precaution, or do I wait and see and chance an accident? TIA.