Our GP made a referral to NHS continence services for my mum who has dementia, and has started similar small ‘leaks’ at night, although she remains in full control during the day. I recently had a phone consultation with them as a result and was surprised at some of the things that could be responsible.
They suggested that she reduce or stop alcohol intake as it can irritate the bladder, causing leakage when it relaxes during sleep. The caffeine in tea and coffee has a similar effect, and they suggested switching to caffeine free brands and avoiding soft drinks like Coke, which contain caffeine. They also suggested that she restrict liquid intake to about 1.5 litres per day and to stop liquids 1-2 hours before going to bed. They suggested that she be encouraged to go to the loo to empty her bladder about an hour before bed, and then again just before going to bed. Mum likes a small glass of wine with her evening meal. It’s only one glass and it’s the only alcohol she has, but I’ve reduced to to every other night and along with putting the other things into practice, so far it seems to be working. The leaks reduced in frequency and have virtually stopped.
You might find some of the suggestions useful, but I would also say check with your GP to make sure nothing else is amiss - mum’s GP did tests to make sure there was no urinary infection before referring on.