- Bangkok (3 days)
- Singapore or Kuala Lumpur (2 days)
- Phuket or Koh Samui (3 days)
- Chiang Mai (3 days)
- Siem Reap (3 days)
You can visit all these places in 16 days highlighted above. They all require full days as mentioned. Additional days can be added for arrival/departure.
Climate varies throughout for this large area but to generalize, between December and April is the best time to travel.