When we stayed at the PPH, we did not have to provide a credit card unless we thought we were going to charge things to the room. (We purchased a package through AAA which included paying for the hotel.) I want to say it was $50 though.
Have never stayed at GCH so don't know the credit hold amount there. However, other area hotels have been as high as $100. This is why I use a credit card and not a debit card for hotel incidentals.