Suppose all 31000 absentee ballots go to Miller. Then he goes into the write-in count with a lead of 17500. So if Murkowski gets only 17499 valid write-ins out of 81000 possible, then Miller wins for sure. A few valid write-ins for Miller will pad his margin. We can always hope.
No, if he goes into the write-in count with a lead over "write-in" then even it the write-in count is 100% correctly cast for Murkowski, MILLER STILL WINS BECAUSE HE HAS MORE VOTES THAN "WRITE-IN".
If Joe gets all 31,000 absentee ballots, then he can't lose, because with the votes that he already has PLUS 31,000 means that he will have 17,500 MORE votes than the 81,000 ballots that are write in ballots.