I have used
cock rings several times overnight. All those
cock rings have been tested during the day and can be worn for 12 hours easily. Smaller sized
cock rings would cause more trouble. However I always wake up if a
cock ring becomes uncomfortable, bugged and sleepy I take it off.
There was a time where I experienced tough erections that happen during the morning. These erections can be much stronger than during the day - coupled with a
cock ring I thought I could throw in a mini work out overnight. However this only worked a couple of times.
I prefer full
package cock rings, currently I am using TOM of Finland silicone
cock rings, mostly the largest version. Whenever I use smaller
cock rings I have to take them off after 30 minutes because of tingling, no matter whether it is during the day or in bed.