Alcohol the following day?

I don't drink at all, haven't had alcohol in many years, early 1980s i think. I do believe it's reasonable for you to consider the effects of zopiclone if you've never had that effect before, but you can't be sure.  You could try drinking the same amount at the same time of day after taking zopiclone the nght before, doing this at home and with someone else there with you, and see if it happens again.  Since you say you got very drunk, i'm thinking your judgement might be impaired so you would want to have someone with you who would not let you drive or walk outside.  If it happens again,  you could also try the same thing without taking any zopiclone and see if things are more like normal, if you did get the weird effect again. 

The effects i got when i was taking were only on waking and wore off quickly, in less than a half hour, at least those that i remember. It was like being in a dream but up walking around, letting my dog out, going pee, doing normal things i would do in the morning, but feeling extremely weird and not being aware that something was abnormal, where the weirdness was the only world i knew--that's the way in which it was like a dream. When i came out of it, i could remember it, and would think how weird it was.  I have read that drinking alcohol and other things can increase the chance of such effects and to avoid combining the two. Like you, i would think this would mean not taking them at the same time.

One thing to consider is how long it takes the body to eliminate all the zopiclone from your system.  Elimination is referred to in terms of elimination half life, which means that half of the dose you took will be eliminated in a certain amount of time, and is called the half life.  The elimination half life of zopiclone is about 6 hours (for the average person, under average conditions). So, if you took 7.5mg at midnight, then at 6am, you would still have half of that circulating in your bloodstream, or 3.75mg.  At noon, you would have half of that whicih would be about 1.8mg.  At 6pm, you would have half of that, which is about 1mg, so the warnings about combining it with alcohol could apply under those circumstances, depending on unpredictable things like individual sensitivities.  People with any sort of liver impairment have longer half life times, and the combination of the two can under some conditions for some people increase the chance of odd effects.  

Here is an excerpt from a website about pharmaceuticals called medicines.org.uk, under the part about 7.5mg zopiclone.  This part was intereting to me because of the kind of symptoms i had.

"Sleep walking and other associated behaviours such as “sleep driving”, preparing and eating food, or making phone calls, with amnesia for the event, have been reported in patients who have taken zopiclone and were not fully awake. The use of alcohol and other CNS-depressants with zopiclone appears to increase the risk of such behaviours, as does the use of zopiclone at doses exceeding the maximum recommended dose. Discontinuation of zopilcone should be strongly considered for patients who report such behaviours."

I'm happy for you that you only take zopiclone a couple of times a week, that isn't very much.