I enjoy my holidays, but sometimes the food aspects are difficult (but I am vegetarian so that along with low carb can be tricky in some countries).
I eat out and eat well, but I choose items carefully, salads etc fresh local vegetables, scrambled eggs for breakfast etc. I find that restaurants are usually really good at swapping items on menus, and almost all have a salad that can be adapted, I like trying new vegetables and variations of salad, and I love cheeses, I will often order the local cheese plate and ask for a bit of salad instead of the biscuits. If you eat meat you could treat yourself on holiday to different meats such as ostrich or alligator.
For breaks away in UK its much easier, breakfast in hotels are easy to do low carb and vegetarian, it is difficult when there is so much temptation on the breakfast buffet but I just tell myself I value my eyesight, feet etc and if I stick to low carb I can enjoy my holiday without feeling ill with high blood glucose levels.
I have a tiny taste of my sons dessert on holiday, but only occasionally not at every meal (actually only if its chocolate based) . I do have an occasional ice cream but I choose a very good quality full fat version (don't have wafer or cone). If we are going somewhere that does a local speciality I will have a small taste, rather the a full serving, so the entire family might share a serving between us.
I test my blood sugar levels and adjust my food accordingly but I don't stress if my levels are a little higher than normal, but we don't go on holiday very often.
I also do more exercise on holiday, walking, swimming, dancing etc.