Hi Kevin,
SP may correct me but I believe the current sketch out of the box supports a screen resolution of 240 x 320 which?may limit you to a 2.8 inch screen size maximum.
I have had a 3.5 inch 320 x 480 TFT working after adjustments to parts of the sketch. so it would not be impossible to use a 5 inch screen if you are prepared to tailor the sketch for that screen resolution.
73,
Bob
