So I think we have at least established the Rolf had somewhere to go. During this time attention was focussed on Viking incursions into Northhumbria, York and the vexation this caused the Saxon kings. What is really missing in historical information from the north. On the basis of the Names of Northern Kings and their place in time. And Who fought what battle against Whom, only the Where and When seems reliable.
People seem to remember bloodshed and mayhem rather well.
But do less well with genealogies. There are sound reasons for this. The church is only just gaining a hold among the Viking culture and dates are starting to matter. The Christian Vikings are being recorded in records, those that still belong to the old belief. Chronology was meaningless unless you had monastic records and you will recall that certain Vikings had a particular love of burning religious buildings.