@MiaN I am currently travelling and also had a holiday in August.
In August we were self catering so I did my own meals when I could and ate prawns, salmon, pre cooked lentils, eggs etc. When eating out I tried to have fish. Also, I kept tracking on Nutracheck (which has quite a lot of chain restaurant meals in it). I picked the nearest meal I could find or even a Gousto or Tesco finest that was quite close. I know it won’t be perfect but the act of recording it helps.
This time I am in hotels but - if you have a fridge - supermarket protein yoghurts, raspberries, nut mix etc can save you breakfast calories. I also bring foldable scales so that I am adding 10g of nut mix not 30g! But if you have a breakfast buffet, things like melon and hard boiled eggs are good.
If your hotel has a fitness room, that helps - and lots of walking if possible.
I haven’t had pudding when eating out and I haven’t missed it. I did have an icecream one day bought by a friend and I ate half of it (truly couldn’t manage more!) and binned the rest. Then I had half a tub of lentil salad and tomatoes for dinner from a supermarket as I was still full. Trying mostly to choose lower carb options and not eating pasta or pizza when out.
I am only about 12 weeks into my journey, a little ahead of you, but I think it’s about what you do consistently, not about a less than perfect day/week.
I am not expecting to lose on this trip - on my prior holiday I put on 0.15kg, but I lost that and more in a couple of days so was probably higher salt and water retention. My goal is to minimise any gain and get back on it when I am home.