I use the full-size iPad but when this croaks I'm switching to the iPad mini.
Call me old-fashioned if you like but I wouldn't leave the ground (including IFR) without paper charts covering the full the route I'm planning.
There is nothing like a paper chart to give an instant overview of a route and any potential complications
Our a/c was ramp checked at Texel last year and the Dutch Feds were most insistent to see a current chart (which was present in the a/c).
Cusco