Solved with a very easy approach.
I override the WizardView get method and I use a session variable to understand if the user want to restore the edit or create a new form
def get(self, request, *args, **kwargs):
"""
This method override the WizardView handling the restore of the session
if the value request.session['restore-wizard'] is True
"""
try:
if request.session['restore-wizard']:
return self.render(self.get_form())
except KeyError:
# just call the default super get
return super(ServiceCreationWizard, self).get(request, *args, **kwargs