The amount of luggage that I usually take to my house to leave used to have me take the train, even though I can’t get any sleep. Then, I usually spend a day or two in Bangkok at a hotel hear the train station. I’d drop my bags off at the train station the day before I flew to Chiangmai. Then, on arrival, I’d stop by the train station (on the way to my house in Bo sang) and get the bags. It’s not that expensive, maybe 300 to 400 baht for 1-2 bags. I’ve never gone from the airport on the air link and get off to get on the MRT to the train station. It looks like it would take an hour each way, hauling at least 1 suitcase that way, which would be a hassle.
I’ll check in as soon as possible on September 3rd, maybe 4.5 hours in advance. If the cost turns out to be 1,000 to 1,200 baht, I’ll pay it and avoid the hassles. If it’s closer to 3,000 baht, I’ll do Plan B.