I see the early wake work schedule presents a difficulty. You are doing pretty much what I would have suggested - try to go to bed as early as possible and rely on bed time techs and obviously not long wbtbs during the week. If you have any natural wakes - like after each or any REM, night toilet breaks, then you may use those as micro wbtb - use techs like mantras, mild, ssild that don't wake you up much but can still direct your thoughts to lucid dreaming before drifting off to sleep. The weekends look like a good opportunity to catch up on sleep as well as incorporate wbtbs. In addition, you can try boosting your chances with more day work - RCs, critical thinking, ADA, autosuggestion.

Have a great time travelling and sweet lucid dreams!