I really think that 4 months old is still way too young to be expected to always make it to the potty pad. I also believe that your baby should have access to food through the night. I would much rather have a pup that still has occasional accidents than risk hypoglycemia in the middle of the night.
__________________  Shannon & Puff 
"All his life he tried to be a good person. Many times, however, he failed; for after all he was only human. He wasn't a dog." Charles M. Schultz |