"extend impact" is correct and usable in written English.
You can use it when you want to emphasize the effect or influence of something over a greater area. For example, "The new policies have extended the impact of the organization across the entire nation."
During our first visit to the area, immediately following the main tephra falls of 26 27 January, residents and business owners were unsure about future eruptive activity and potential extended impacts and disruptions.
On November 5th, 2015, a tsunami of slurry engulfed the small district of Bento Rodrigues, loading the Doce River and its estuary with toxic tailings along a 663.2 km trajectory, extending impacts to the Atlantic coast.
Rachel White said: "The Guardian has demonstrated the incredible impact of its journalism time and again, and the potential to amplify and extend that impact even further is huge.
How does the company extend the impact beyond its shows?
Now, with history under his belt, he can go on to cement his place and extend his impact on South African cricket.
Making customers a "community" can "extend marketing impact through advocacy," the site argues, and "more effectively support customers through peer sharing".
It's also clear the games industry has changed significantly since id's heyday in the late 90s, and Hollenshead concedes the company has struggled to extend the impact it once enjoyed beyond the platform that made its name.
The best dishes were both starters: an oriental crispy pork salad with a sticky but not oversweet sesame dressing, and lots of leaves to add greenery and texture and extend the impact of the sauce.
In those cases, policy announcements can be used to extend the impact of conventional policy instruments.
After the Meeting: Follow-Up You can extend the impact of a face-to-face meeting with thoughtful follow-up.
