I don't think the scenario you describe is a realistic scenario within the European energy market. Prices are decided by supply and demand and the market is getting more interconnected so single points of failure become less likely.

I do wonder what happens in case there is no wind and no sun all over Europe and the demand is higher than the supply. It's probably very unlikely to happen but then countries will prioritize their own citizens (as we saw now during the covid crisis) and then we could have blackouts. I assume scenario's like these have been researched but I don't follow this subject, maybe someone else here knows?