Our book club picked a 600 page doorstop and 4 people quit by week 2

We voted on the next pick back in January and the winner was this 600 page historical novel that only 3 people had even heard of. By the second meeting, 4 of our 11 members had bailed and one of them flat out said she read the first 80 pages and felt like she was doing homework. I get wanting something meaty but we meet at a coffee shop in Portland and half the group has kids, so a book that takes 3 weeks of grinding just is not realistic. Now we have 7 people left and everyone is too polite to say we should have picked something shorter. Do you all set page limits before voting or do you just let the group pick whatever wins?