Already booked October 5-10 in Hanoi.  Then I plan to do 2+ weeks exploring the Northern mountains:  Cao Bang, Ha Giang, Sapa.  Taking bus or trains between towns, then doing some motorbike touring (possibly a 5 day tour of Ha Giang loop) and some trekking at each stop. Returning to Hanoi sometime between 25-29 October before flying to Chiang Mai on 30 October for 17 days in Northern Thailand followed by 4 weeks in Lao PDR beginning and ending in Luang Prabang from 17 November to 13 December.  My dates for each of the three countries are firm, but my schedule within each is still very flexible.   I’ve been to VN twice since 2018 but haven’t yet made it north of Hanoi. I’ve also been to Thailand twice and Laos 3 times in recent years.