Where can over age 65 airline pilots fly? Some countries have no maximum age for airline pilots while many other countries specify age 60 or 65. (Austria, Russia, Canada, Australia, etc., have no maximum age)

ICAO rules currently specify a max age of 65 which allows ICAO member states to fly into countries where the max age is only 60. 

Does this rule apply to only landing and taking off, or also to in transit overflights?

For example, could a flight depart Canada, overfly American airspace, and fly to Australia with crew members older than 65? 

If not, what about a flight from two bordering countries like Canada to Russia?
Pilot qualification- including age limit - is according to the law of the country where the aircraft is registered. What a pilot must abide by when flying overseas is the local operating/air traffic rules.