Wow, thanks everyone for your quick and informative replies, this is such useful information and had started to panic that we would be out of options!
Thanks for the update on Parking4cruises Martha1974 and amajaa, I have a much better feel for how it all works now as in the past have only used ABP parking so the dropping off the car etc is all new to us. It does sound like a great choice. Good to hear from someone that has used Penguin, thanks Devoncruiser82, really appreciate you taking the time to post. Thank you too favouriteplaces, feel much more reassured to hear about your experience and I don't think I would have found that particular Holiday Inn and it would be a lovely relaxing start to the cruise!
Thank you so much everyone for posting, am feeling much more prepared now and really looking forward to our first Princess Crusie!!!