Blockade is being extended to Hydro Extrusions which supplies the Berlin Factory.

https://sverigesradio.se/artikel/if-metall-utokar-konflikten-mot-tesla-varslar-om-blockad

The cars power electronics will tend to have it’s peak efficiency at close to its maximum output. This is how most such power electronics work out.

Additionally if it is cold the battery must be heated to be charged whic reduces efficiency more the slower a charge gets, but this is mostly an issue in freezing temperatures so it might not apply.

Rest assured that any charge speed less than 0.2-0.1C will be neglible wear due to charging speed. Essentially any charging on AC will be slow charging for most cars.