I know u mention the oats , but I also train at 5.30 am so have 35g raw weight oats and a scoop of whey ,25g carbs 25g pro at 4.45am ,I do this whether dieting down or bulking before weight workouts only ,cardio is done fasted .works very well for me.i have tried simple carbs pre workout but crash badly half way through workout usually
Good luck