This is a fabulous pattern. I would knit it just for the brim. Love it. I was participating in a “Shrink It” KAL and wanted to make a cap for an American Girl doll. This fit the bill. I decided to do a baseball cap rather than the one shown but used the same elements.

Project Notes
Using the smallest size.
Cast 70 st on with 2.75mm (US 2) needles
Work 4 rows of rib
On 5th row BO first 5 st rib to last 5 stitches, BO 5 st (60 st) I used straight bind off.
Change to alternate yarn.
Starting from wrong side, work 5 rows flat Stockinette
Then increase 1 st each opening edge next row and every alternate row 3 times for a total of 6 rows ending on purl side (66 st)
At end of next row cast on 4 st (70 st) placing marker after second cast on stitch.
Working in the round, knit for 2 inches in total from beginning.
Begin decreases.

Brim
Using 2.5mm (1 1/2 US) continue in pattern.

Having done this once, I think I would be tempted to do 2 more rows to the brim.