Would really appreciate any recommendations for a buggy/travel system that can work well as a single or double. My daughter will turn three shortly after baby is due to arrive. She has some minor additional needs so is likely to require access to a buggy if we're out and about until she is about four. She'll be at nursery during the day when baby arrives which is why I want something that will work well as a single too. We have the old version of the uppababy vista at the moment (2013) which we love but it doesn't convert easily to a double. Was thinking of the newer upper baby vista but would others recommend this or are there any other options? Thanks