Thanks for your response and advice Ed.
Most of the group will be from S. Mn, but not all. Our sister from CO, her husband, their son and his wife, and their 3 young boys will be with the 2013 group.
The group is open to anyone anywhere. Sis has staterooms reserved and can usually get more depending on demand/availability. The last group cruise I did, she had her largest group ever: 70. One couple have been on every "Cold" cruise I've been on. There are quite a few repeat group cruisers, but always new people too.
Everyone was cheering at her on-board cocktail party when she announced she would arrange more Celebrity "Get Out of the Cold" group cruises. I found a roomy in this site who is from S. Carolina.
I've cruised "alone" with the group twice and still had a great time. Would sure be nice for my $$ to go toward more tours and fun activities:-)