Short answer
Yes, it is more serious. A cat with compromised kidneys is less able to process and eliminate toxins, so even a tiny amount of alcohol can cause disproportionate harm. Alcohol is rapidly absorbed and can lead to dangerous drops in blood sugar, body temperature, and blood pressure, which a sick cat may not tolerate. This is an urgent situation; do not wait for symptoms like wobbliness or vomiting to appear. Contact your vet or the ASPCA poison line at 888-426-4435 right away for guidance.
Alcohol — Food safety facts
Do not feed · Cats · full breakdown on the linked food page
Ethanol poisoning in pets is fast and serious — a small amount of spirits can be fatal to a cat.
The full verdict, portion guidance and serving notes are collected on the Alcohol food facts page.