Thanks everyone for your replies. I have been reading them all carefully and considering what I want to do. To answer a few questions that came up:
Amy, you're right, I don't want to lie to her. I have been trying to find a kind but honest way to deal with this.
And yes, the reason we have not just "cut ties" with them is because of mutual friends and acquaintances. The organization we are a part of is very small and used to be close-knit. It wasn't really necessary to cut ties with them before because we only saw them once a month (if that), and I was able to make small talk with Pearl for a minute and then move on to socialize with someone else, as did she. She didn't feel excluded, and I felt I could tolerate that level of interaction. Dave was not a problem for DH in these situations because he really only talks to one or two other members while at a meeting (and he never talks to any of the women).
I got a call from Pat yesterday too. Pearl called her as well. Pat ignored it, but Pearl left essentially the same message. Pat called me to warn me and told me that neither she nor Jay wanted to spend time with them either. So, taking in all the PP's advice on the group concensus, I cannot include her on our day outing against the wishes of Pat. So, I plan to tell her that I already have plans for all three days. Pearl does not know that the three of us already have a day of shopping and sight seeting planned. Hopefully, they won't be able to get seats near us at the event, so she won't know that we're all gone that day.
As for the tickets, I found out last night that we don't have them yet. They are in the mail, so I can honestly tell her that I have no idea where we are sitting. I will not give her Jerry's contact information, but I will tell her he is out of tickets and I will give her the number of the vendor so they can purchase their own.
Assuming they can get tickets through another resource, can you arrange a brief outing with them early on, such as breakfast or lunch?
I am guessing the reason you are not simply cutting this couple dead is because you have mutual ties that would make this awkward in the long run. Throwing them a bone would a) keep hurt feelings at bay - they won't be able to claim you snubbed them, b) allow the other couple in your party to get a taste of their "charms", thereby getting them on board with avoiding them at other times.
I wondered, too, if you might be able to get together with Pearl and Dave for just one meal, just to keep the peace. The trouble is, that meal would open the door to all kinds of awkward questions, like "What are you guys doing later?" and "Why don't we get together tonight?" I'd either not get together with them at all, or perhaps schedule something with them near the end of the event.
I think maybe we could schedule something with them near the end of the event. I will bring it up to DH and see if he will talk it over with Jay and Jerry. I'm pretty sure that both Abby and Pat would be willing to concede a breakfast in order to keep the peace and enjoy the rest of the event.
After last night's conversation with DH, it looks like this October may be the last time I have to interact with Pearl and Dave at all. DH is thinking that it would be best for us to withdraw completely from club membership. Since that is the only way we know Pearl and Dave, we would not be getting together with them at all.
I'd ignore the call but warn the others that she may call, and talk with the others to make sure you're all on the same page regarding her. Otherwise if she somehow calls someone else and says "Oh the others say they'd love to meet up with us!", you may find yourself meeting up with her.
I really don't feel I can ignore the call. The bolded part is why I feel I should respond, so that she doesn't just call people until she gets a "yes." To me, that's just as bad as leaving a vague, open-ended possibility "Oh, maybe we could get together, we'll see when we get down there..." kind of response.
I plan on calling Pearl back today. I don't know her schedule so I don't know whether I'll get her voicemail or not. But, what I plan to tell her (basically) is: "Jerry is all out of tickets, the vendor's number is -----. I have no idea where we are sitting, as we have not received our tickets yet. I already have plans for all three days of the event."
I guess we'll see how it goes. :-) Thanks for the help.