Hi Hollye,
i was having the same problem with DS using huggies over night, poor thing sleeps on his tummy and would be wet right through and all the way up to his neck!!
i have since started buying huggies in the next size up for night times, and no more wetting through and waking up cold!!
so maybe you could try that? just buy a small pack in the larger size and see if it makes a differance?