That Villa on Soi 11, and Soi 33, seem flexible based on folks I've chatted with.

Yes, it seems like many of the regular bars are staying open until 03:00, and another 1 hour until 04:00 with the doors closed. Obviously the pop-up sidewalk bars operate until the last customer passes out, but maybe they have to close up by 06:00? I usually see them wheeling their bars back for storage ~ 07:00 when I drive out.

I was in Foodland/Soi 5 this morning and they wouldn't sell prior to 11:00 AM - they have some decent wines on sale this week; you may be able to buy a beer at their lunch counter off-hours as that qualifies as a restaurant, I think?