There are several options for meeting both of them. They are together at the Adventurer's Outpost in AK, which you can get a FP+ for. They also greet separately (along with Goofy) at the Character Spot in Epcot. You can get FP+ for this as well. As far as character meals, they are both at Chef Mickey's at the Contemporary Resort and at Hollywood and Vine at Hollywood Studios. Mickey is at 'Ohana at the Polynesian, the Garden Grill, and Tusker House in AK, but no Minnie. Minnie is without Mickey at the Cape May Cafe at the Beach Club.