Question

insert dashes where needed.
\i plan to climb the highest peaks on all seven continents in yes, in six months,\ the climber told the news reporter over the phone.

Explanation:

Dashes are used here to set off an abrupt, emphatic interruption that emphasizes the surprising time frame. The phrase "yes, in six months" is an interjection that needs to be separated for emphasis.

Answer:

"I plan to climb the highest peaks on all seven continents in — yes, in six months," the climber told the news reporter over the phone.