The best advice for cheat days is to plan for them. If you know that there's an occasion or work event coming up and you'll find hard to resist temptation then decide how much indulgence you are comfortable with, enjoy this and then get back to your plan that evening or the next morning. This is real life, it doesn't mean you've "fallen off the wagon". If you think you might struggle to get back on track, prepare a delicious meal prep before the event so it's as easy as possible to get back on track afterwards. Your body reflects your eating habits not these one off occasions so don't sweat it.
If you're going out for a drink make sure to arrive hydrated, skip on the alcohol in favour of an alcohol free treat or alternate alcohol with water. This will help you to enjoy fewer drinks than you would otherwise have. Save yourself money and brain fog the next day.