I think the speed limit upstream is 6mph but you cannot always achieve this due to river conditions, locks, other boats etc. Also you cannot travel at night. Though it does say on this website that you should be able to cruise from Tewkesbury to Stratford in two days http://www.canaljunction.com/canal/severn_avon .htm
To travel through the night is dangerous , what if you are really knackered and fall off into the prop? doesnt bear thinking about..also if its a hire boat someone will probably inform them you are travelling in the dark.. insurance would be invalid Can i ask why the rush?
Taking all of those points into account can anybody tell me how far a barge is likely to get in 48 hours travelling from Tewkesbury to Stratford? (in miles if possible)