How much more alcohol is in ice beer than regular beer?

There is no such thing as "ice beer". This is a common misconception.

The term "ice beer" is often used to refer to beers that are cold filtered, which involves chilling the beer to a very low temperature to precipitate out proteins and other particles that can cause haze.

Cold filtering does not change the alcohol content of the beer.

The alcohol content of a beer is determined by the amount of sugar that is fermented during the brewing process. The temperature at which the beer is served or filtered does not affect this process.

Therefore, there is no difference in alcohol content between a cold-filtered beer and a regular beer.