The New York Times provides a state-by-state chart timeline for voting by mail:
But 16 states allow voters to apply for mail ballots so close to Election Day that their votes could be at risk of being too late if they are sent and returned through the Postal Service. Officials in these places recommend applying for and sending in ballots early, or dropping them off at local election offices or in secure drop boxes if available.
In Minnesota, voters can request a ballot the day before the election, too late to be mailed to them on time. But if voters request their ballots early and postmark them by Election Day, they should arrive in enough time to be counted. Montana has the same deadline for requesting a ballot but does not accept those returned after the election.
The takeaway is that you should vote early to make sure it counts. I’m just going to do it right when the ballot arrives.