It will be runnier when it's defrosted but just add some more flour to bring it to the right consistency and add some baking powder to help it become crispy batter when fried
Unless the folks recommending the freezing have had personal experience with its success, I'd be sceptical, since there are a number of things in the recipe that won't freeze very well if at all... the beer, the oil and the egg whites. Egg whites collapse and turn a yucky, runny mess, even when refrigerated for very long... But... good luck!