Bigger front wheels

[AliGUY]

I tried this question in the trucks section but two days and no answer.. so im just gonna rephrase it here

If i throw like 20 inch wheels that are really wide on my mustang (yea i know they would'nt fit; buts lets say i make em fit) and after driving a bit the front wobbles every time i break is it cuz those rotors are taken in allot more heat from the wheels because of the increased surface contact-- which im thinking would lead to greater friction and heating on the rotors cauzing them to warp....???

so... if i was to get cross drilled rotors (same size) would that help.. or would the best option be to just simple upgrade to bigger size rotors???