How to switch back and forth between iphones?

Ok so I have an iphone 5s right now. My 6 Plus is being delivered this week. I'm going to switch over to the new 6 plus. However, next month I'm going to Asia for 3 weeks. So I want to leave my 6 plus at home and bring the 5s to asia (mostly to use in the airport and on Wi-Fi while over seas, etc) then when I get back home to CA, I want to switch back to the 6 plus. Is there an easy way to switch back and forth between phones?

Use icloud and make sure everything is backed up. When the 6 plus comes select restore from Icloud backup instead of setting up as a new iPhone and keep Icloud on and everything from the 5s will be on the 6+ and visa versa