L'Estrange represented Western Australia at the National All Schools Cross Country Championships three times.

The seat had been held by conservative independent Liz Constable since 1991, dating to its time as Floreat.

In September 2016 he was also appointed as Minister for Finance and to the Government's Economic and Expenditure Reform Committee.

Following the Liberal Government's defeat, he was appointed Manager of Opposition Business in the Legislative Assembly and Shadow Minister for Mines and Petroleum; Economic Development; Defence Issues; Innovation and ICT; Science.

In June 2019 he was appointed Shadow Minister for Corrective Services and Housing and elected to the Parliament's Community and Justice Standing Committee.

At the 2021 election L'Estrange was caught up in the Liberal Party landslide defeat set amongst the backdrop of COVID-19; however, it was to be a significant boundary change - removing the blue-Liberal area of central City Beach and replacing it with the Labor-red area of Scarborough-Doubleview that saw 205 voters preference flows defeat him.