I do know of such a widget but it doesn't seem to have notifications:

https://github.com/gooGofZ/BitcoinTimechainWidgets

Alternatively, you can use nostr's friendly and smart fee bot: nostr:npub1j9k220uxarsuc7fj9kp2cs9yahetqy4q6m9cdatn5srkwk6mr6tqcy7e8k