Per the SOS election results page, 1,815,963 ballots were cast statewide. Looking at the statewide races anywhere from 1,770,000 and 1,970,000 votes have been tallied. That leaves anywhere from 20,000 to 40,000 untabulated ballots.
https://results.arizona.vote/#/featured/33/0
That’s not accurate. (neither is the 800,000 remaining)
In 2018, total votes cast in Arizona was 2,384,308.
That’s a good approximation for how many ballots was cast this year.
So far there is 1.93 million votes counted.
So there should be about anywhere from 400,000 to 500,000 left to count.