"Digital piano" and "electronic piano" are really the same thing. You'll find from the Yamaha site that the P series are called digital pianos. Some will categorized as stage pianos. Certain sites selling keyboards will term them opposite. Whatever it is, the 2 are really the same thing.
You sound like you want to compare portable digital pianos and non-portable digital pianos. As for the Clavinova and P series, they are not really comparable. You yourself pointed out accurately that one is portable while the other is not. If you want to compare sounds, it depends on which model in particular you are comparing. The CP series (which is replacing the higher-end P series) have more sample/note making the piano more realistic than the lower-end P series. Same for Clavinovas - the lower end may just have the basic AWM piano sounds but the higher end ones take on the newer generation of piano sounds. Because the higher end Clavinovas has pretty good speakers, they try to recreate the resonance inside the piano with their speakers and acoustics, something the P or CP series cannot just because of how they are made (ie without a piano body - although they try to recreate it digitally within the sample).
Same for touch. Higher-end Clavinovas has real wooden keys. They will definitely feel different to the P series and other portable digital pianos.
In short, it is hard to compare the Clavinovas and the P series as they are quite different breed of animals.
Don't know if this answer your question.