Well on the one hand I say: Why didn't you set your Steam into offline mode or disable automatic patching for the game?
But on the other hand who knows what this patch might change. You need to know this because your current work may need to be adapted to work with the patch.
So we and you have to sit through this, wanted or not. I hope you get your modem / connection up and running again soon. Did your provider gave you any date when the signal strenght will get back to normal or when they will finish reparing the destroyed umts transmitter in your region?