Check that
- the engine is running properly and that fuel consumption is normal
- there are no leaks (fuel, oil or other fluid)
- the brake pedal is functioning properly
- all lights work
- tire tread depth and air pressure are at correct levels. Change to snow tires when driving in areas where there is a risk of snowy or icy roads
- the start battery is sufficiently charged
- the wiper blades are in good condition
It could also be a good idea to make sure the maps in the navigation system* are up to date, and to check requirements for vehicle loads, ferries, car trains, etc.
Keep in mind that data roaming charges may apply if the vehicle is connected to the Internet while in another country or service area.