Could a Boris Johnson Premiership be shortest ever?

When Mr Johnson moves into Number 10 tomorrow he’ll inherit an overflowing in-tray. Not least the immediate political challenge of trying to govern with such a wafer-thin majority, while trying to make good on his pledge to deliver Brexit and deal with some pretty challenging international crises at the same time. So how long can he hold down the job? Could parliament try to get rid of him? Or might he risk calling a general election?