Here is the recipe Sarah followed to use all of 2 skeins of Horizon. To make a larger shawl, use 2 skeins of each color - 4 skeins total.

There are other modification options available, including striping at the end to avoid running out of yarn inconveniently rather than partially completing sections. See Size/shaping section and Modifications section of pattern.

Recipe:
Complete Sections 1-3 as written.

Section 4:

• Complete 1st wedge as written.
• Complete 8 Wedge rows of 2nd wedge (ending with Wedge row 2 - knit to end but do not pm.)

Section 5:

• Complete Setup (stripe) rows 1 & 2.
• Complete Setup wedge row but do not lock in CC1 strand (just knit and pms as written).
• Complete 8 Wedge rows of 1st wedge (ending with Wedge row 2).
• Skip to Final section row (knit to end) -- you should be back at the right edge of work, where CC1 strand is.

Binding off: Bind off across all sts with CC1 using Jeny’s surprisingly stretchy bind-off.