I thought RSS feeds might come to the rescue, but I dug and dug and dug through the various options, but didn't find any one solution that perfectly fits what you're looking for.
Here are the things I found that are sorta close:
- Feed of active questions from all sites where you have an account
https://stackexchange.com/feeds/tagsets/${filterId}/my-sites?sort=active
- To find your specific filter feed URL, you'll need to go to https://stackexchange.com/filters/my-sites, and then copy the URL from the link that's at the bottom of the page, to the right of the pagination buttons:
- Feed of a single site's "hot" questions:
https://${site}/feeds/hot
- Feed of "hot" questions from (all?) sites across the Network:
https://stackexchange.com/feeds/questions
The only kind of feed I found sortable directly by score is the site-specific tag feed, unfortunately, which isn't super useful for surveying multiple sites:
http://${site}/feeds/tag?tagnames=${tag-or-+tags}&sort=votes
Of these, I think the closest thing might be either the Network-wide hot question feed, or using a feed reader to group together individually selected site-specific hot question feeds together, though I realize this isn't exactly what you're looking for.
is:q score:100 answers:3
which delivers, alphabetically by site, 60k questions that have a 100+ score and at least 3 answers. But that's huge, probably not fun to sift through.