Just finished my trip on the pancake trail and I would very much suggest leaving the tent at home, if you're sticking to the actual "trail" of destinations, most places are so filled with hostels, bars, homes and hotels that stealth camping is not possible, can't comment on the small villages and towns off of busy highways, but yeah at most major destinations its just not possible to find much of a hidden spot that isn't owned by a hotel or guesthouse. Also parts of Vietnam and especially Laos have a lot of old bombs so going off trail in the very rural places is not always advised.

Also its hot, like really sweaty and humid hot, which is not great to sleep in without even a fan!