Any team going on a run needs a few things to break their way. The Rangers were very fortunate with their 1st round matchups in 2014 and 2015. They were fortunate that Price got hurt in 2014.
At the end of the day, they need luck, as well as needing to close out their business in less than 7 games. Colorado looks like the way more rested and faster team. The Rangers' road to the final is never going to be easy. They'll still have Toronto and Carolina that they will likely run into every year in addition to Tampa and the Pens that still may hang around and continue to give them fits the next couple of years. Colorado got really lucky McDavid went ham on Calgary. No doubt in my mind Calgary/Avs would have gone 6 or 7.