Just take Baby Rudin and a serious stack of paper with you on these holidays and you should be set.

My two experiences of de-brainrotting:

1. Doing a pilgrimage walk in Japan with a cleared phone home screen. Only the Gaia GPS app on there with the route, and some other local weather and mapping applications. No consumption of anything external during the day. Just steady walking and eating and looking around. It was excellent. You can probably do this anywhere given the right context and commitment.

2. We slept several nights in a hut at 2100m altitude in the Austrian Alps just out of range of cell reception so the icon on my phone was "satellite" all the time. It turns out that without the possibility of communication or fresh input, you can read a bit on your kindle in the evening and then go KO at around 22:00 sleeping like a rock until 06:30. Such an amazing amount of rest and refreshment just from a simple accident of geography.