Snow flake hat and booties

I have this pattern for baby’s Snow flake hat and booties it has 6 mo. In parenthesis (13 1/2 inches hat circumference) and I was considering making them for my nephew which I believe is almost a year now. They are in a pattern book called coats and Clark at www.coatsandclark.com. It says directions are for newborn, changes for size 6 mo. are in parenthesis. 5 mm knitting needle it is to be made with exact color of blanket.

My question is how big would I have to make it from a year to 2 years, say 2 winters. Winter now and maybe next winter, longer if possible.
It calls for Red heart super saver which is 4 or 5 in weight. I would be using Bernat baby coordinates to match the blanket I just made him for Christmas which is 140 gram in weight, 5 oz yarn I don’t see a number. Also how much yarn would I need?
I really think it would look awesome with the star blanket I made for him and plan on giving it at Christmas. Questions for booties also. Apparently it only uses 3 oz of the Red heart super saver yarn which is 7 oz med. worsted. If you need more info. let me know.:knitting:

Thank you KSH

Here’s a link to some hat sizes for 2 or 3 year olds that may help.
http://www.bevscountrycottage.com/size-chart.html#hat
The best way to figure out yarn equivalents is to go by the gauge required in the pattern and the gauge recommended on the yarn ballband rather than the yarn number or the weight in grams