Regardless of destination or ages of your children, you have to plan accordingly. Sometimes you don't have any choice and will have to travel long distances with your family. This is my case and I'll share some of my thougths.
If you are going to SE Asia, you'll most likely have a stop somewhere on the West coast. I'd spend the night in LA or SF and let you and the baby rest before taking on the longer flight (13+ hrs). That way you can also reload on baby supplies, sterilize the bottles, pacifiers, cups and let the baby move around (exercise) a bit. Airplane rides are too much on their little bodies. Remember that these days the time spent at the airports is almost the same (or more) as the time you'll spend flying. If you feel tired after a long flight, you can imagine how the baby feels.

I've flown plenty of times from the West Coast of the US to deep South America (work). In my experience, flying with:

- an infant: (+) easier to handle; sleeps better; will cry but can be soothed; easier to change diapers in bathrooms; one type of food-milk; (-) more stuff to carry; baby ears will feel pain due to pressure; can feel motion sickness; exposure to germs; you will worry a lot and will not rest.

- a toddler: (+) can walk; will eat anything; can go bathroom with some assistance; will require less on-board supplies; can be entertained with activities- books, crayons; can sleep full 8 hrs; can haul his/her own backpack with toys, etc; don't need a car seat (-) can have tantrums; can be picky about food; will kick the seat and play with the tray; will make noise; can feel motion sickness; tired toddler=cranky

- Both infant and toddler: (-) extremelly challenging.

Everything is possible but it all depends on your level of confidence. You'll have to accept the fact that there's not a perfect way to travel with children. You will have your horror stories later to tell your friends, but you'll also remember the awesome trips you've taken with your kid(s).