(Edit: Sorry, I just realized you aren't on insulin and this post is about it. But the info might be useful to someone so I'll leave it up. But I think it also points out one of the serious advantages of insulin over the oral hypoglycemics. A situation like this is easy to handle with insulin.)
One unit of insulin brings down my blood glucose readings by 10. There is a lot of variety in this because of different stages of insulin resistance. Don't assume your body will react on the same scale. If my reading is ever above 100, I immediately inject enough Humalog to bring it back down to 85.
This took a bit of trial and error to find out. It sounds like you might not have that worked out yet. But it would seem a safe call that you need a little more insulin. If you can't get to a medical professional because of the holidays, the safest thing to do might be to just add a little rapid acting insulin. Allow a generous margin for safety. Winding up unconscious isn't fun, and I haven't experienced dead from an overdose of insulin, but I don't expect that to be my idea of a good time either.
Keep track of how much you added and how much it has brought down your levels 4 hours later. It won't take too long to get a good idea of how much each unit of insulin brings down your blood glucose.