Choosing a long book when reading time comes in 20-minute chunks

The novel I want to read is nearly 800 pages. My reading window is twenty minutes before bed, and I worry I'll forget the secondary characters between sessions. On the other hand, a long book might be exactly what makes that little daily window feel like a proper escape. Have you found it easier to read sprawling books slowly but consistently, or do shorter novels fit fragmented schedules better? I'm curious whether note-taking ruins the pleasure or actually helps.