I decided that if anything I was going to be short so I've knitted the back, front and sleeves up to the armhole and no further. I figured that I would definitely have enough yarn for that and if I run out, I can buy something similar to finish it off. Contrast might even be better. Then I'll have a different problem to cope with, that of the thickness of the yarn, not the length. I'll worry about that when I come to it.
Time for another picture:
This is how the front panel knits up.
I'll be back to show you how I'm getting on later.
In the meantime, sometimes I knit up a scarf...