Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Chiang Mai to Milan Malpensa Airport as you normally would.
For a flight from Chiang Mai to Milan Malpensa, you will be flying from Chiang Mai. Chiang Mai (CNX) is just 3.1 km from the centre of the city. Chiang Mai is the only Chiang Mai airport and it handles 0 outbound flights to Milan Malpensa per day. 0 airlines have flights to Milan Malpensa from Chiang Mai on a regular basis.