Is it necessary to transfer 65,000 baht each month for the Non-O retirement visa extension?

If they didn't give you the affidavit back so you can use it again, you need to get another one from the Canuck Embassy here so you can apply for the year extension.

You can apply in Chiang Mai for a year extension when you have 45 days or less left on your current 90 day stamp from that Non-O visa

𝗦𝗵𝗲 𝘀𝗮𝗶𝗱 𝗻𝗼𝘁𝗵𝗶𝗻𝗴 𝗮𝗯𝗼𝘂𝘁 𝘁𝗿𝗮𝗻𝘀𝗳𝗲𝗿𝗿𝗶𝗻𝗴 𝟲𝟱𝟬𝟬𝟬 𝗲𝗮𝗰𝗵 𝗺𝗼𝗻𝘁𝗵. 𝗜𝘀 𝘁𝗵𝗲 𝘁𝗿𝗮𝗻𝘀𝗳𝗲𝗿 𝗿𝗲𝗾𝘂𝗶𝗿𝗲𝗱?

NO, no transfers are required, you use the income affidavit as your embassy still issues it

AND

You can continue to use the income affidavit each year without having to transfer in any money.