How to protect a Cha-based caster against Feeblemind?

Feeblemind requires an Int save: on a fail, the target’s Intelligence and Charisma are set to 1. This pretty much destroys any Int or Cha-based caster, but the fact that the latter have low Int (and are not proficient with Intelligence saving throws) makes them especially vulnerable.

What are some ways to handle this? The route I’ve taken with a Sorcerer concept is to start as a Rogue for my 1st level (for Int proficiency) and then go Sorcerer from 2nd level. Other ideas welcome.

My goal is to learn what options there are to prevent getting Feebleminded, be it at character creation, or a magical item, or… anything that helps resist it. E.g., it just occurred to me that, while expensive, L9 Globe of Invulnerability will prevent it (and duration could be doubled for 1 sorc point).