I agree with Waldo. I don't know, however if the kit wines are balanced for higher alcohol regarding acidity. You might run the risk of getting a very "hot" wine and a wine with more or less only the taste of alcohol.
I have heard of people trying this, but again, you have no warantee on the kit anymore. I don't know if I would do it or not, but since I'm a curious person by nature, and since I cannot follow directions well, I personally would try it, step by step.
What I mean is if the normal abv for this kit wine is, say, 7-8%, try tweaking it up to 10% first. You get a notion of what it would taste like, without ruining it (possibly) completely. I'm not sure about the yeast that is used in this kit wine, but it might have a very low alcohol tolerance.
If it tastes good to you after it is finished, try the next one at 12%...
I know that the kit wine manufactures and others would see this post as bad advice, but if your fingers are a-itchin', I would do it this way.
M.