What are the best tips for a same-day border run from Nakhon Si Thammarat to Sadao?

A user in Nakhon si Thammarat is seeking advice on doing a same-day border run to Sadao as their paperwork for a non-B visa is not complete. They have already utilized their visa extension and need guidance on the trip, including if it is feasible to make the border run in one day or if an overnight stay is necessary. Comments provide insights that a same-day border bounce is possible with sufficient cash (20,000 baht or equivalent), a confirmed flight out of Thailand, and a valid accommodation booking. Others suggest alternative routes like going to Satun and taking a boat to Langkawi. However, they caution that Sadao can be busy on weekends and that requirements can vary.