Those are the worst conditions. the warm weather just kills it with the melty-refreeze thing. I hate it because it 'looks" solid but it's actually ice once you dig even slightly. First person gets the traction if there is any then the rest are hosed..
We did Bunce School a few years a go like that and basically just pulled cable the whole way up the hill. Winchfesterooskey. Sounds like a very similar day except ya'll were on a more technical trail to start with.