As far as I know, there's no late night coffee to be had anywhere east of I-43 or anywhere near the East Side/North Shore area. The sidewalks get rolled up at 10 p.m. The only exception I know of is Caribou at Bayshore Town Center, which is open until 11 on Friday and Saturday nights.
The only recommendation I could offer is this here Starbucks at 27th & Oklahoma, which is open from 5 a.m. to 11 p.m. Gosh, it would suck to have a close/open here! To reach this store, especially if you're close to the lake, your best bet is to take the Lake Parkway to Oklahoma, then go the two or so miles west to 27th. Otherwise, take I-43/94 south to the Holt exit.