Italy has 60M people and paper ballots, results are out the next day. Population does not matter since polling stations can be scaled up proportionally.
I've been in voting where we had a dozen ballots per person (referendums) so this would be more than the total paper ballots in the US, it works fine.
Minor miscounts happen but nobody has ever seriously questioned the overall vote results.
Uh no. This election I had a president, two senators, a state senator, a state assembly, a county executive, city council, school board, prosecutor recall, and half a dozen ballot measures. It took four legal size paper surfaces.
Some of the regional elections in Germany have comically large ballots with dozens of options and a very complicated counting system (16 votes that can be split between individuals or party lists). The hand-counted results are generally available by the next morning. There is really no excuse for using electronic voting. In Germany it has been ruled unconstitutional since it cannot be checked by the voters.
Those could easily be prioritized. First count the federal elections, then the state elections, then the county elections. You get the presidential and congressional results within a day, the state election results within two-three days, and the more local ones within the week. Is anyone going to seriously complain that it took a week to find out who is on the school board?
I've been in voting where we had a dozen ballots per person (referendums) so this would be more than the total paper ballots in the US, it works fine.
Minor miscounts happen but nobody has ever seriously questioned the overall vote results.