Like the OP said, the microtransactions will probably move to LTC, DOGE, DASH,... since their blocks won't be full, so their fees will be much lower.
People here are very hyperbolic when it comes to the fees. It is not like they fees are going to increase tenfold over night just because blocks are full. It will take a while before more than half of the blocks mined are full. This is if we assume that nobody is doing anything in order to increase the capacity (which is obviously false).