The "Heroes" promo code should save you a nice chunk, about 20% to be exact. I just did a comparison and it took a really cool KidKamp suite from $319 a night (2 adults, 1 child, 1 infant) down to $255 a night
Here's a break down on what the heroes discount is for all my LE, military, and yes, those fire guys too:
Rate for Armed Forces, Law Enforcement, Fire, and EMS workers. Must present valid ID at check in. Limit 2 rooms per ID. Limited number of rooms available for each date. May not be valid during holiday and blackout periods. Multiple night minimum stay may apply.
In this case the Groupon seems better but that's for a basic room so I would use the Hereos rate and go for the cooler looking room. Although that $50 credit would come in handy too, because I here its crazy expensive.
CLICK HERE to check it out & buy on Groupon:
For further savings, think about leaving the resort and hitting up a local place for food.
As a side note some friends stated instead of doing Great wolf they drove over to Idaho and did Silverwood for less then Great Wolf costs. I'll be doing some research on that too!