Snow water melt into rivers is a triple whammy. Road salt, road muck plus very cold water, and sometimes extra silt make a 'snow broth' that puts the fish off the feed. But I've sometimes found that when it does fine down, with the fish not having fed for the duration of the cold snap, that the fishing is exceptional.
Talk of no further sport before the end of the season is premature. If we do get a thaw then expect no more than a week or two of disruption at most. In Feb 78 we had well over a foot of snow yet a rapid thaw with very warm rain 3 days later gave us a big flood yet bagging up 4 days later despite the high water. The river had icebergs less than a week before.
