The European electricity system enters the winter of 2022-2023 facing challenges such as reduced availability of French nuclear power, lower than average stored hydro energy and possible gas shortages in the power industry. These challenges limit the amount of energy available to the system during the winter and reduce the system's ability to meet peak demand and. This study quantitatively analyses the security of electricity supply in Europe (with a focus on Switzerland) between November 2022 and April 2023 by simulating electricity generation and trading under various supply and climate scenarios. To provide a conservative analysis, we exclude certain measures such as demand reduction targets and fuel switching efforts. The results show that Europe, and France in particular, can avoid transmission congestion and power shortages in the event of reduced French nuclear availability. However, in a cold winter, supply shortages may occur in gas-dependent countries if reduced French nuclear availability is combined with gas generation being limited to historical levels. Furthermore, if a 20% gas saving is enforced, Europe could face supply shortages in various weather realisations. On the other hand, Switzerland faces few challenges even in cold winters with the reduced availability of French nuclear and the implementation of 10% gas savings in the electricity system. This is due to the flexibility of the Swiss hydro system and trading opportunities with neighbouring countries.