Thailand during the holidays isn’t bad. Most Chinese travel on group packages and almost exclusively end up in specific destinations, and I think that you’ll find hotel prices during CNY don’t change much..the influx isn’t significantly more than the normal tourist prices and it’s more of a seasonal thing than a CNY thing. Singapore has a few days during CNY where prices skyrocket (hotels) because it’s also a locally celebrated holiday for 3 days or so, but no more so than one of the many international events (like the sg grand prix).
Don’t count out places in-between – less international destinations..lots of people choose to backpack/go through Laos/Cambodia/Vietnam during the holiday where very little Chinese tend to go, and there are little/no 大陆 celebrations going on. Can fly to Kunming early and bus down.