An interesting and wonderfully FREE campaign system for the ECW:
"Tinker Fox - an English Civil War campaign game of garrison warfare in the England, Scotland and Ireland, 1642-1652, using the BATTLEFINDER card system (also for use with Very Civile Actions)"
http://perfectcaptain.50megs.com/tfox.html
Tinker Fox uses an interesting strategic movement system which abstracts the area into key areas. This allows you to do away with detailed map movements (and get on the with the business of dispatching those rebellious Roundheads!).
Pretty neat. I would also consider going further and 'cut' some of the linkages between sections (for deep river etc) to make strategic chokepoints.
One can see this interesting system (with tactical games resolves with a C&C variant). Very interesting with some nice ideas for Campaigning
http://prometheusinaspic.blogspot.com/search/label/ECW%20Campaign?updated-max=2014-12-30T20:59:00Z&max-results=20&start=8&by-date=false
Alternatively, the Napoleonic rules "Blucher" include a short campaign system which would also give an interesting game with less preparation required:
SCHARNHORST: The Campaign System
Blücher includes a campaign system called Scharnhorst which acts as a pre-game. Players plot the movement of their columns along roads and across the countryside. They must make the difficult decisions about spreading out their forces to control key points, while remaining within supporting distance in order to mass for a battle once the enemy has been located.
Of course your opponent may not let you fight on the field of your choice, with all the forces you would like. Was it wise to have sent so much of your cavalry on reconnaissance now that they arrive late and fatigued for the battle? Did you neglect to secure a key road or town in the rear of your position, forcing you to fight at a disadvantage?
Scharnhorst does away with the traditional wargame roles of “attacker and defender.” The players script the battle with their own choices of maneuver and objectives, and the fortunes of the campaign may change dramatically once the fighting is underway.