941.237 Carrying handgun where alcohol beverages may be sold and consumed
applies to a "tavern" (bar, restaurant, festival w/ alcohol license)
http://docs.legis.wi.gov/statutes/statutes/941/III/237
A licensee may not carry concealed & consume alcohol on the premises.
Zero.
941.20 Endangering safety by use of dangerous weapon
http://docs.legis.wi.gov/statutes/statutes/941/III/20
(1) Whoever does any of the following is guilty of a Class A misdemeanor
(b) Operates or goes armed with a firearm while he or she is under the influence of an intoxicant
940.09 Homicide by intoxicated use of a vehicle or firearm
http://docs.legis.wi.gov/statutes/statutes/940/I/09
(1g) Any person who does any of the following is guilty of a Class D felony
(a) Causes the death of another by the operation or handling of a firearm or airgun while under the influence of an intoxicant. (am) Causes the death of another by the operation or handling of a firearm or airgun while the person has a detectable amount of a restricted controlled substance in his or her blood.
(b) Causes the death of another by the operation or handling of a firearm or airgun while the person has an alcohol concentration of 0.08 or more.
939.22(42)
http://docs.legis.wi.gov/statutes/statutes/939/I/22/42
"Under the influence of an intoxicant" means that the actor's ability to operate a vehicle or handle a firearm or airgun is
materially impaired because of his or her consumption of an alcohol beverage, of a controlled substance or controlled substance analog under ch.
961, of any combination of an alcohol beverage, controlled substance and controlled substance analog, or of any other drug or of an alcohol beverage and any other drug.
http://docs.legis.wi.gov/statutes/statutes/941/III/23/3/d/_4
To "go armed" does not require going anywhere. The elements for a violation of s. 941.23 are: 1) a dangerous weapon is on the defendant's person or within reach; 2) the defendant is aware of the weapon's presence; and 3) the weapon is hidden.
WI v. Keith (1993)
So... "materially impaired" can probably be proven at any BAC if they have video of you doing stupid human tricks, or lots of reliable witnesses to your impairedness.
The only absolutes stated in the laws are:
1) 0.08%BAC
2) "a detectable amount of a restricted controlled substance"
Notice that you can be impaired by legal drugs just as much as by alcohol or illegal drugs.