I'm not sure I understand what you need (I mostly leave both on), but you can turn wifi off with one touch of the wifi quick tile. You can turn off cellular data with two clicks: one of the carrier tile; one at the top of the following screen.
I'm running Android 7 beta 5 on my Nexus 5 and if I want to turn on "mobile data" which is usually off, I pull down a single notification bar and the second icon is mobile data. The first icon is WiFi but I never turn that off.