If it was outside all winter it may not have survived. Trim off the dead leaves and then, once new leaves/shoots are showing, prune back any dead wood to these. Leave it until the end of summer before giving it up for dead.

I have one Maureen, it's planted outside, been there for over 3 years and it was fine through the past 2 (hard) winters.
However, i am in the south west and .... it's planted in a sheltered, south facing, well draining position.
I think unless all those factors are supplied the likelihood of it being safe through winter in 'your' region would be a different matter altogether.
I pruned mine very drastically last year and it was fine, so if 'do' have to prune back hard, it should be okay.

It 'is' annoying when they give misleading information on labels.