I would say that brickwork is certain to all come crashing down.
What is the roof construction?
If it is just steel angle or wood beams supporting a flat lightweight roof, a fresh length of 2x2" heavy angle, clamped or bolted to the roof beams extending the full length of the door, plus the window, with one or two timbers fixed to support the angle iron, would allow the brickwork above both the window and the door to be taken out and replaced with one long lintel across the door and window. You could then install new brickwork above the lintel and fit a complete new window made to measure.