Thoughts on booking hostels/accommodation in advance in SEA

Hi all

I’m planning on going to Thailand, Vietnam, Loas and Cambodia for ten weeks starting in June this year.

I was wondering what are folks thoughts on whether or not to be book accommodation in advance of my trip. I know it’s rainy season so it won’t be as busy but I have seen conflicting posts about places being booked up or places being very expensive when booking last minute

I am the type of traveler where I am going to have a pretty detailed itinerary and my route mapped out before I go and I will do this regardless just for me mentally. I know the argument and I say most people will say to not book things in advance cause I may like some places and not others. And for me the biggest worry is the weather. I know that will hinder some activities. I am not worried that if I book places couple days in advance that I won’t find accommodation but that the bad hostels will the only places left

I did a solo 6 week interrail trip last summer and book all trains and hostels in advance and never found myself annoyed that I had done that. I’ll liked that I had the mental stress of organisation already done and I had booked hostels that I had liked.

Just wondering some folks opinions that have done either options. I think I am more of the side of having most accommodations booked but I am worried about the rain interrupting my stay at a location and wanting to stay there an extra few days. Anyone’s experience during the rainy season would be a help

Is there any places/activities that you would say are a must book in advance?