When will we know the EC vote results?

https://www.archives.gov/federal-register/electoral-college/key-dates.html

(snip for the pertinent parts)

December 28, 2016

Electoral votes (the Certificates of Vote) must be received by the President of the Senate and the Archivist no later than nine days after the meeting of the electors. States face no legal penalty for failure to comply.

If votes are lost or delayed, the Archivist may take extraordinary measures to retrieve duplicate originals.

On or Before January 3, 2017

The Archivist and/or representatives from the Office of the Federal Register meet with the Secretary of the Senate and the Clerk of the House in late December or early January. This is, in part, a ceremonial occasion. Informal meetings may take place earlier.

January 6, 2017

The Congress meets in joint session to count the electoral votes. Congress may pass a law to change this date.

The Vice President, as President of the Senate, presides over the count and announces the results of the Electoral College vote. The President of the Senate then declares which persons, if any, have been elected President and Vice President of the United States.

If a State submits conflicting sets of electoral votes to Congress, the two Houses acting concurrently may accept or reject the votes. If they do not concur, the votes of the electors certified by the Governor of the State on the Certificate of Ascertainment would be counted in Congress.

If no Presidential candidate wins 270 or more electoral votes, a majority, the 12th Amendment to the Constitution provides for the House of Representatives to decide the Presidential election. If necessary the House would elect the President by majority vote, choosing from the three candidates who received the greatest number of electoral votes. The vote would be taken by state, with each state having one vote.

If no Vice Presidential candidate wins 270 or more electoral votes, a majority, the 12th Amendment provides for the Senate to elect the Vice President. If necessary, the Senate would elect the Vice President by majority vote, choosing from the two candidates who received the greatest number of electoral votes. The vote would be taken by state, with each Senator having one vote.

If any objections to the Electoral College vote are made, they must be submitted in writing and be signed by at least one member of the House and one Senator. If objections are presented, the House and Senate withdraw to their respective chambers to consider their merits under procedures set out in federal law
(snip)
https://www.archives.gov/federal-register/electoral-college/key-dates.html

You don't say.

any defectors?

Beyond that.... very unlikely.

the House then chooses the Pres. and since the House is majority Republican, they can just vote Trump, or Pence, for Pres. and nothing really changes the outcome.

+/- 1 percent

All the electors meet in their respective state's capitol buildings Monday morning and given the interest the media will know the vote totals in the afternoon.