This is a large blanket (check the dimensions!). Instructions are provided in the pattern to modify it for other sizes. Simply add or delete repeats to make it bigger or smaller and stop knitting when you are at the length you want!
You should be able to substitute different yarn weights as well, just knit a swatch with the needle size suggested on the ball band and go from there.
I am more than happy to answer questions you have about this pattern.

UPDATE 3/26/16: Since Needleworks is no longer in business I have posted the PDF of the pattern.

Finished Size 52” by 72”

Yarn: 6 Hanks of Cascade Ecological Wool
(478 yards/hank)

Needles: Size US #10 (6.00mm) or size needed for
gauge

Gauge: 20 sts and 26 rows worked in pattern = 4”
after blocking