Some yeast may have survived. So, you will likely make beer, or worst, have to repitch if it's all dead. But, you can't possibly know your innoculation rate, so you could be severely underpitching. This could harm the beer or make it undesireable to consume. You could do a starter, crash and decant it, that'd give you a better idea of how much healthy yeast you have. Lots of threads in the stickies on starters.
I always look at it as a financial equation- you spend $30 - $40 on ingredients, is it worth risking that coming out poorly over $8 it would cost you to buy a new yeast pack? Or just buy dry yeast, then you're looking at only a couple of bucks.
With the investment in time and ingredients in making a beer, plus the 6 weeks it typically takes, I go conservative- I'd just buy new yeast and count it as a lesson learned.