For a week’s stay at a gay country house, a young woman will find herself in need of no less than three hats—one a prettily trimmed walking and traveling hat; one … for golfing, boating, or picnicking; and one of more delicate construction suitable for use with light afternoon frocks, for tea parties, etc.

Encyclopaedia of Etiquette: What to Write, What to Wear, What to Do, What to Say, A Book of Manners for Everyday Use
Emily Holt, 1915

Perhaps I can save you a bit of room in your trunk by offering a hat that can be worn several different ways. Both sides of this fabric look lovely, so you can wear it with either side facing out. Try it with the brim folded up for a closer fit or with the brim unfolded for a bit of slouch. With all those options, it might just be enough to see you through a whole week without reinforcements.