Need some solutions for toddler sleep

Hi ladies,

My son is 22 months, still sleeps in a crib and wears a sleeping bag. Lately, his sleeping bag has been coming off because he moves a lot while during his sleep and so the snap button comes off and he manages to wriggle out during the night. This in turn upsets him and a couple of nights he wakes up crying (he never wakes up in the middle of the night).

Does anyone have a toddler in their crib still but with pillow and blanket? Is this possible even though he moves around a lot?