Kelly, when I was first looking into Cavaliers and talked to many, many breeders, I always received the same message. They are "companion" animals and suffer terribly when separated from their humans. Oliver's Breeder wouldn't even sell a pup to a home that did not have someone there all day, every day. It is part of their make up, and personally I think even more prevalent in ours who suffer from SM/CM.
Henry's Breeder, although friends with Oliver's Breeder, was a little less concerned about Cavaliers and separation. I do think Henry deals with it better than Oliver, but it's hard to tell, as he has always had Oliver as a companion. As Oliver has aged, he is better and better with it, but I could not see myself ever boarding him in a kennel, especially before he was 5, and can only barely entertain the thought now if he is with Henry and I find a particularly loving facility.
Even though Georgia is sleepy, and didn't come home with any flares after her recent visit, I think she can manage her grooming appointments once in a while. Isn't she alone when you go to work? Of course, being in a strange place and having things done to her that she doesn't like very much, will make her more tired as she is "concerned" while there. Oliver always seems so happy after his grooming appointments, but he hasn't been in a long time...too long in fact.
I don't want you to feel guilty. It is like taking your child to the Dentist. No, they don't like it, but it's a necessary evil and they do survive it. Your Groomer sounds like a very caring person, and as long as Georgia comes out the way you wish, but a bit sleepy and clingy, then she's doing alright. You've also travelled with her which would add to her changes even though she loves your Mum and enjoys being there.
I do think they settle as they age. Each time will become easier and easier. I do know and understand how you feel, I really do.