The Heptarchy was
Kent
East Anglia
Mercia
Wessex
Sussex
Essex
Northumbria
By the arrival of the Vikings, Sussex,Essex and Kent had basically been subsumed by Wessex. East Anglia was subservient to either Mercia or Wessex depending on which was stronger at the time and Northumbria was a basket case but still strong enough to deter Mercia from attempting a take over.
With no Vikings or a different Viking conquest you could get Wessex, Mercia and Northumbria still independent of each other in the 11th century (possibly East Anglia as well) but given the way continental trade was developing a Wessex takeover would have happened by the end of the 11th century if only by its King being the Bretwalda.