How to best extend WiFi over 100m?

Hi all,

just asking a question on behalf of my dad.

They currently have WiFi installed in a car mechanics garage, but need it extended about 100 metres (to be on the safe side) to reach a portacabin from where they will be setting a mini office up for sales.

What is the best way you can extend the WiFi connection over this distance? There are no buildings in the way of the current car garage and the cabin that they are having done. It does not need to be ethernet as long as the WiFi connection is strong.

Thank you.

Any questions, then please ask.