Hey Ned, cyclists 2 abreast taking up 1/2 lane is nothing. Cyclists can take up the entire lane if they like:

https://www.ontario.ca/document/official-mto-drivers-handbook/sharing-road-other-road-users#section-1

which says:
When passing a cyclist, drivers of motor vehicles are required to maintain a minimum distance of one metre, where practical between their vehicle and the cyclist. (See Diagram 2-11.) Failure to do so may result in a fine in the range of $60 to $500 and an additional two demerit points on the driver's record. Whenever possible, you should change lanes to pass.