hi trollover
im doing what you want to do, here in Nha trang (tulip hotel), sit on my balcony and work then go swimming and chilling. wifi is excellent here, had 1st powercut last nite about midnite which lasted for 1/2 hr (1st 1 in 2 wks) i think most cafes have wifi, but i dont bother as i have excellent connection here, buy my own coffee so dont need to venture out.
all the major tourist areas across vietnam have wifi, as does thailand, laos and cambodia
have fun