As long as the diaper is not too full or on the verge of leaking it's okay to leave the baby in a wet diaper all night.
Lots of babies and toddlers go through the night and sleep in a wet diaper although some babies may pee more and need a diaper change in the middle of the night.
You can also use overnight diapers which are more absorbent or double diaper the baby.
You don't have to or need to change a diaper after every pee.
If the baby or toddler is wearing a disposable diaper then there's no need to change the diaper after every pee.
Changing a diaper after every pee is wasteful and gets expensive.
With a disposable diaper you can leave the baby in the wet diaper for 2 to 3 hours until the diaper is full enough to change.
Disposable diapers absorb the wetness so the baby or toddler will not feel wet with one or 2 pees.
With cloth diapers you may need to change them as soon as they pee or after a few pees but with disposables they can safely wear them until they are full.
If you're worried about diaper rash then you should put some baby powder on the baby or toddler which helps to absorb moisture and keep the skin drier.
Some people do change their baby or toddlers diaper after every pee but it's not necessary to do so and is just expensive and wasteful.
Disposable diapers are meant to absorb the pee and lock the wetness away so you can wait until the disposable diaper is full of pee before changing it.
However after a poop unless the baby is sleeping then you should change the poop diaper right away.
But if your in a car or cannot change the poop diaper right away it's not gonna hurt the baby or toddler to sit in their poop for a little while until you can get somewhere to change it.