I got my information from Clinical Pharmacology, and they don’t have any interactions listed between SMZ-TMP and Ethanol. I haven’t heard of the disulfiram-like reaction with Sulfa drugs before, but you do have much more clinical experience then I do (as in you have a lot, and I have almost none), so can see you seeing more of the rare reactions.
If you do get a disulfiram-like reaction, you’ll know it really quick. You’ll start to feel like you have a hang over within about 20 minutes after drinking. But, as Qadgop said, it is normally not life-threatening. If you drink on the medication, and start getting nausea or vomiting, as long as you stop drinking then, you’ll be fine, and know you’re one of the rare people with the interaction.