Firstly I am sorry to hear of the injuries sustained by your wife and I sincerley hope she makes a full recovery.
The fact that the crash occured on a B road really makes no difference, it all comes down to evidence and whether anyone was negligent in failing to maintain the roads given the conditions.
The bottom line is probably no. The local Highways and council have a duty of care to keep the main arterial roads clear and where possible free of snow and ice, B class roads have a much lower priortity.
The only people a clain could be made against would be the local authority or Highways, and the defence would be that your wife should have driven appropriately for the conditions (and I do not mean this in any disrespectful manner), and if the car rolled several times, the the chances are the speed was inappropriate for the conditions which were knnown to be bad at the time.
As a specialist accident investigator, it s something I have come across on many occasions, and I would be very surprised to find someone prepared to take the case on as there would be less than a 50% chance of success, unless it could be proved that several accidents had occured at the same spot before your wife had hers, it had been reported to the council and they then failed to respond and grit the road.
If there were no previous accidents and nothing was reported to the local authority, then there is no one to claim against I am afraid, as the local authority would simply apply the statutory defence.
