As of yesterday, 301,024 Republicans had turned in absentee ballots in Florida and another 288, 025 had voted early.
Rudy Giuliani's campaign tried to collect absentees early -- before voting started. They were moderately successful, according to the campaign's tracking. Since Giuliani's core pool of supporters is said to overlap with McCain's, McCain is said to be at a disadvantage here.
Mitt Romney's campaign tried to collect absentees late. Initially, they hoped that Romney victories in Iowa and New Hampshire would boost their efforts. Whoops. BUT -- victories in Michigan and Nevada and Wyoming and Romney's enduring viability probably helped their collection.