Here ya go. It'll take a little bit of work since you'll have more than one rectangle, but hopefully, the calculator will make things a little simpler.
There is no right way to knit; there is no wrong way to knit. So if anybody kindly tells you that what you are doing is "wrong," don't take umbrage; they mean well. Smile submissively, and listen, keeping your disagreement on an entirely mental level. They may be right, in this particular case, and even if not, they may drop off pieces of information which will come in very handy if you file them away carefully in your brain for future reference. ~Elizabeth Zimmerman
One thing you can do if you want to "save" your Kureyon for the body of the bag is use a solid color of something feltable in a coordinating color, like Lamb's Pride or Cascade 220 (the not superwash types) for the bottom of the bag. If you double-strand the solid color as well, it will make the bottom especially sturdy.
There IS a way to figure it out, but it takes a spreadsheet and a lot of brain work. calculating total number of stitches of the original compared to number of skeins used...
Here's what I would do. I would start by making the handle. That's going to need to be done no matter what.
According to my quick spreadsheet I setup, you should be able to make it 45st by 34 rows by 70 rows tall w/o any problems. It'll probably turn out a little bit taller than 70. but you should be safe making it that big.