How to wake them at night

Lynne
I have to admit, I LOOOOOVE my sleep so I tend to let my baby sleep a little longer in between feedings in the early morning. He's 7 days old and would sleep through the night if I let him. The problem is, I wake up to feed him when it's been about 4-5 hours since his last feeding but it takes me about 40-60 minutes to even wake him up enough to feed him. I take his clothes off, change his diapers, put cold things on him, wipe him down with a cold washcloth but nothing works. Is it absolutely necessary to wake him? Are there any other tricks for waking him? I'm exhausted and trying to wake him for an hour makes me even MORE tired. That was time I COULDVE been sleeping. 
Thanks in advance for your advice!