Contemplating Camping with Toddler and Dog

[spongefingeranyone]

After some sleep stuff recommendations please. Already have a double airbed but have read that it may not be the warmest option, nor smallest, so may well invest in a SIM. However, it's the sleeping bag thing that has got me puzzled. DS is 15mo and sleeps half of every night in with me at home. Goes to be in his Grobag in his cot and then wakes in early hours and snuggles in with me. So, camping wise I'm wondering whether I'd need to have a big enough sleeping bag for him as well as me? A double? Or would that be overkill. Dog likes to snuggle up too (Westie). A Mummy sleeping bag would be too small wouldn't it. And even if DS kept in his Grobag and snuggled up to me, what sleeping bag is best for me, square shaped bottom or mummy shape one? And what about the SIM, are they all single?

Lots of questions, sorry, but TIA for any advice.