Ropey

Word of warning, Don Muaeng immigration queues are horrendously long these days, anticipate an extra 1-2 hours queuing after the plane lands. On the bright side, you won't really hit any rush hour traffic until into the city as you're going against the flow Sent from my DUK-L09 using Tapatalk

Another option is to buy a portable WiFi, buy a data Sim at the airport when you land and have the shop put it into the portable WiFi. Then you keep the phone with your UK Sim, but connect to the portable WiFi which is running from the Thai data Sim. These devices are small enough to fit in a pocket easily and will need charging after about 12-18 hours depending on the model you buy. Sent from my LG-H860 using Tapatalk