Yep, Jan is chockablock, top of the peak season. However, there's so much accommodation around that not everything gets booked out, so I'd keep on searching via internet. If you don't want to be too near the action, look at Karon & Kata, they're 2 popular beaches that are not too hectic. Avoid Patong. If nothing comes up then go back to Bali.
Just out of interest 2 ladies I have know for many years made their first trip to Thailand in Jan this year, previously they have made many trips to Bali. They spent 3 weeks in Thailand, at Phuket, Pattaya & Bangkok and they told me over dinner that they disliked Thailand and would stay with Bali in the future. They found the language barrier annoying, plus they felt the Thais didn't like them. They told me in Bali they make friends with Balinese people and often sat around all night drinking and talking, and Balinese shouted them drinks. In Thailand every interaction they had with Thais involved them getting their purses out and paying money.