lol, once a week feedings are fine, but I can't exactly tell you how large or fast your snake will grow in a year or two.. I fed mine every 5 days as a hatchling, then 6 days on fuzzys, and he's now on once a week feeding with hoppers. and I can tell you that my boy has grown quite a bit! he was 15 grams when I got him on Nov and he's now just over 100 g and about 2 and a half feet long about the width of a highlighter at his thickest part.
what I CAN tell you is that your snakes should be about full adult size by 3 years of age.. and they usually Max out at about 2-3 inches girth wise, and males reach anywhere from 3.5 to 4.5 feet, and females are usually larger reaching about 4-5 feet in length.. 6 feet with any corn is pretty rare.
I hope this sorta gives you guys some sort of an idea..