Find out the breakdown of your extract. It may contain crystal. If so, you may want to dramatically reduce your 2.25lb of additional crystal.
Good idea but I want to get the ABV up to 10% so if I reduce the Crystal wouldn't I have to increase the extract?
If the extract has too much crystal + the amount of additional crystal you're planning to add, you may not get your final gravity as low as you'd like. Therefore, the ABV will be lower than planned and the beer will finish with a sweeter taste, as The Professor points out. Not a bad thing with this style of beer, but not sure if you're going for that.
Also, make sure to use lots of healthy yeast for this big of a beer. I did a large winter warmer a couple years back and used lots of amber and dark extract. The beer finished over 7% ABV, but was awful wine like. Not good in a beer. Too much crystal and unfermentables in the extract and poor yeast management. I now keep my extract batches fairly simple and low ABV and do all grain batches for anything creative.