Take the time to recharge
If you have trouble with a lot of stimuli, you know that you also need time to recharge. The way stimuli are experienced and the amount that makes you tired differs from person to person. You often know for yourself what you can handle and how much time you need to recover. When we think of a holiday, we quickly think of relaxation, but that can be quite disappointing. Especially if you are someone who likes to see something of the country.
You are not a whiner
If you are with a group of like-minded people, it is easier to plan rest days than if you are the only one who likes to have low stimulation. Especially in the latter case, it is tempting to just carry on, just like everyone else. After all, you do not want to be a whiner. To make it a bit easier for yourself, it is wise to indicate in advance of the holiday that you also want to have days or moments when you do not want to do anything. This way, they already know about it and it is easier for you to indicate that you need rest. And even though it may feel a bit like nagging, you know for yourself that you need it and that it won't get any better if you continue, just like everyone else.
Alternating
You can alternate between stimulating and low-stimulation in different ways. For example, you can plan a day full of stimuli and take it easy the next day to recover from it. For example, visiting a big city is usually something you do all day, but there are also many stimuli there. The next day you can then quietly go into nature or even spend a day lounging around at the cottage.
You can also approach it differently, by planning something that brings a lot of excitement and/or impressions on the same day and then finishing with something relaxing afterwards. Take the almabtrieb, for example, which is always a big party, but generally doesn't last a whole day. At some point, all the cows have passed by and you still have enough time to take a small walk in nature, or do something else to recover.
Differences per person
Everyone is different and that also applies to how you can deal with stimuli. Not everyone benefits from variation. For some people, a little bit is already too much and they even prefer to avoid (intense) stimuli altogether. For yourself, you often know best what works and you should stick to that. Participating is fun, but being able to keep going on holiday and not coming home feeling wrecked is perhaps even more fun.