My Belle slept about 18-20 hours a day, and Bobby was a little more active, sleeping less maybe 18 at the most.
Dogs can be very adaptable, especially the cavalier, which is why they make a great family pet... they are sporting and playful and can go on walks, etc. and are cuddly and can sleep away their days when there is nothing else to do.
I always feel bad when I am working and see them snoozing away on the sofa, I feel that I'm not giving them enough stimulation, but it's their choice to sleep, they play and snoop around when they want... but sleeping is indeed a priority!
Desrae, guardian of two tri-coloured cavaliers, Belle 3 years old and Bobby 1 year/8 months.