If it blows at a cylinder seal into a water passage, you will get massive pressure in the expansion tank, massive coolant loss, misfiring, significant power drop and a lovely steam cleaned spark plug on that cylinder.
If it blows across water and oil passages, you will get mayo in the sump and oil in the expansion tank.
If it leaks from the edge of the gasket out of an oil or water passage, you will get oil sweats or pink crusties on the block.
Head gasket failure on the TFSI is very rare.