I can't decide if I need a single or double. We have a Maclaren & BJCM and my girls are barely 3 & 6 that would potentially need it. I know the 3yo will need something but I'm not sure about the 6yo. Should I rent a double? Normally, if the 6yo needed a break, she either gets a turn in the stroller or lets the 3yo sit in her lap. If I only take a single, which would be better the Maclaren or BJCM?