I read elsewhere today that Johnson is supposedly consulting an election expert to call a general election, but on the 31st Oct, so we would go out of the EU by default, without any MPs to oppose it.
The PM can no longer call a GE. Thanks to the FTPA, it has to be a decision of two-thirds of the House - in other words, it needs Opposition support. The only other option is a vote of No Confidence (which also has to be moved by the Leader of the Opposition).