assume your hypothetical sheet of paper has thickness 1u; on fold iteration 1: thickness of the paper is doubled, 21u = 2u on fold iteration 2: thickness gets doubled again l, 22u = 4u

this pattern continues for all subsequent iteration and by the seventh iteration the thickness of the paper is 2^7^ * 1u = 128u

hence by the seventh iteration, assuming you have managed to reach this far, you will be trying to fold something that is 128 times thicker than your first fold.

also whether it be DIN A4 or DIN A1 it doesnt matter, the ability to fold is dependent on the thickness of the paper, which is the same.