Find the Large Attachments Eating Up Your Gmail Space
chrome.google.com
chrome.google.com
Also one can reach the google script app with direct url:
https://script.google.com/macros/s/AKfycbyBlGOLsoNB_aoZkVGkO...
Or shortUrl:
"has:attachment larger:20M"
Just use a search like above, and adjust the size down as you need to pull more items into the search.
(Not saying the chrome extension might not be easier, but sometimes you're at your phone and also might want to do this.)