are you talking London-Brighton-Oxford, or Brighton-London-Oxford, or just Brighton-Oxford as the title.
And on or offroad? If offroad, proper, or towpath touring (or both?)
I could envisage Brighton to Oxford as a decent 2 day run with options for fun on the way if time / legs allow.
Day 1: Brighton to SDW to Downslink. Up to Cranleigh from where you can go on to the destination (Guildford – has Travelodge and Premier Inn) or have a play in the Surrey Hills and then onto the NDW and W to Guildford.
Day 2: Guildford over the army lands to Swinley, outskirts of Bracknell up to Twyford – Henley – Nettlebed – Goring or Wallingford.
From there my knowledge runs out but you’re only 15-20 miles from Oxford and you could even do Thamespath for that bit.