Not really. The electoral college doesn’t report until about 6 weeks after the election.
Can declare them essential and if they don’t show up fire them and replace just like Reagan did to the air traffic controllers.
More than enough time to get ballots delivered even with new staff.
Based on commentary I saw last week....even if ‘all’ ballots were returned the day before the actual election day...the examination of the returned ballots (whether they would be qualified or disqualified) and then the counting (not just for President, but for Senators and House Members), would be delayed.
The states without the mailing business will function as normal, with Trump probably getting 20 states declared that evening. The rest of this won’t happen in November, and with court challenges....maybe not till January.