Answer:
This is not possible
W = width of cardboard to start with
W+6 = length of cardboard to start with
H =2 (height of finished box)
volume = W x L x H = 14 in^3
if H=2 in, then the area of the base before cutting out the 2x2 corners is W x L = 7 in^2
This is not enough area to cut out the 4 corners of 2x2 each, which would be 16 in^2