Well, let's try another way.
When entering Cyrodill you could choose what version do you enter.
It could break immersion, but it could not. The system could remember your last choice and put you into world of your choice, there could be system option to change.
So Cyrodill at peace could be nice, PvE only and dull?
Cyrodill at war could be dirty, fired, NPC could be killed also.
I do not think that limiting PvP makes sense - if someone loves PvP then limiting his access does not make sense
Just to note - personally I like PvP, but some people might not and I respect it. Also this could give cheap additional world space for PvE players.
Anyway I think there is no chance to start Cyrodill at PvE version - even if somehow magically everybody votes for it the development is too far, just idea.