JamesA

Call Thai in the USA and book your BKK to Chiang Mai with them, get them to mail you the ticket, don't go for an e-ticket as a 'hard' ticket best when you check in all the way to CM, they will be able to confirm to you for peace of mind that when you check-in in NYC you will be checked 'thru' to Chiang Mai, and they should issue boarding pass and check your baggage thru, you will pass Immigration/Customs at Chiang Mai.
Chiang Mai to Yangon is an irregular schedule, I think 2 x per week, if you are flying the long haul with Thai my personal suggestion would be to route yourself back thru Bangkok and fly to Yangon from there, Thai has twice daily Bangkok to Yangon and that sure beats a 2 x per week!! so from Chiang Mai route yourself back to Bangkok and then do a Bangkok-Yangon return with Thai. So Thai will give you a BKK-CM return and a BKK-Yangon return. You then elimate all those worries over the baggage.
But on the subject I would not bring too much with you in the first place as no doubt you will want to do lots of shopping, you only need light clothing and laundy even at hotels is fast and cheap. I would pack as light as possible, 1 suitcase should be more than enough, then when you do your bits of shopping in CM and I pressume before you head home from BKK just buy another case locally, they are so cheap. Remember baggage is 'per person', I see no reason to arrive in Thailand with anything more than 1 case anyhow.
I really would seriously do the CM to Yangon back thru Bangkok, then you can plan your trip and not have to worry about days that the CM-Yangon might or might not fly, CM to BKK is 1 hr 10 gate-to-gate and BKK to Yangon is just 1 hr 20. If you do that sector Business you will then get lounge access at Yangon which will be nice.

I did a new thread othwerwise we were drifting too far from Kbfree's post

glorialf

Thanks- James. I had already planned on going to Yangon via Bangkok but it's a lot cheaper to do Bangkok-CM-Yangon (via Bangkok) Bangkok than two round trips. But I could rethink it all. I wanted 7 days at the end to have clothes made but if I went for a couple of days after Chiang mai I could have the initial stuff done before Yangon. Something to consider. It just means two more trips to and from airports.

I used to travel with one large bag and then bought a second on in Bangkok. I switched to the two bags last trip to avoid having one bag that was "too heavy." I know I should learn how to pack light and I always have good intentions but it never works.

rhkkmk

plan to leave one bag at your hotel in bkk while you are off to the two other cities...that's what we do and it works well...when you return to bkk in between just repack for the next leg..free at most hotels..and safe..

Kathie

James' idea of requesting routing to CM rather than to Bangkok is a good one, but if you are using ff miles for a free ticket, I don't think it will work.

glorialf

Problem solved. Oriental will meet me at international and take one bag which I'll fill with my winter stuff, dressy stuff and stuff I want to have copied or altered (I'm hoping to lose a lot of weight before this trip)and take it to the hotel where they will check it until I get there. I'm sure I'll have to pay the car fee but that's a lot less than $1,200 and it will give me peace of mind! My friend whom I'm meeting in Chiang Mai (she's flying Cathay) can do the same thing._

Phew! Thanks for both of your ideas.

JamesA

Well there you are, glad it's all sorted. I am still watching out for the 340-500 aircraft to arrive and will let you know as soon as there are any seat plan details.