Building 700 sq ft granite patio in Connecticut. Wet or dry set?

I want to built 700 sq ft granit patio using 2' by by 3' one inch thick granite slabs.Two thirds of the area has existing concrete over it . 40 years old but holding with some cracks .
Should I just remove concrete it and lay stone over aggregate and sand or pour more concrete and mortar all the stone.
The concern with wet ( mortar ) set is that it might crack after some times due to our thaw/ freeze circles.
Any knowledgeable advise?
I've done a lot of research but wondering if some had expirience with it,

Thanks for your replay. That's what I want to do. The existing slab is sloped away from house . Every contractor said I need to put it on cement , don't see why I couldn't just ad sand and stone dust and lay on it