Easy solution to this problem. At Yankee Stadium, you can't enter if you appear to be intoxicated. You can take a breathalyzer if you feel that you've been unfairly tagged by security. Same policy should be implemented and actually enforced here for both day and night games. This would take care of most of the parking lot drunks and allows normal people not looking to get drunk to tailgate.
During all night games (start times 4pm and later), limit alcohol sales to pregame and the first quarter just like Saturday night. That allows responsible people to enjoy a couple drinks during the game and prevents the idiots from becoming too intoxicated (many of which can't afford to get too drunk on stadium beer anyway). There haven't been too many issues with the 1pm games so sell until halftime as usual for those.