Thank you all for your ideas. You inspired... a new NPC.
Shenta d'Ghallanda, also known The Golden Voice of Surrender, Foggy Bottom Town Cryer & Enforcer of the Peace
Mark of Hospitality halfling, Background House Agent (Insight, Persuasion)
Wizard 20 (of course, who isn't?), Enchanter.
INT 14 CHA 20 WIS 14 DEX 14 CON 10 STR 8
ASIs: Diplomat, Telepathic (INT), Linguist, Empathic, 1 ASIs.
Skills: Insight, Persuasion, Arcana, Investigation.
Among its trait, she gets the Ever Hospitable, giving her +1d4 to Persuasion checks. She's of course racially Lucky.
As a Wizard, She took as a signature spell Enhance Ability, casting Eagle's Splendor on herself every hour on the clock.
She's tasked with patrolling the Foggy Bottom roads and enforce peace among the spellcasters. A drunken fight between level 20 wizards could spell doom not only for the village but for civilization itself. Shenta has learnt the story of the Netheril and the little-known fact that Karsus's spell originated from a bragging contest in a fine brewery. She definitely doesn't want the spell outcome for her adoptive village. Raised among house Ghallanda, she also took over the village inn after planeshifting to Faerun during the course of her youthful adventures.
Originally, the Council of Liches wasn't very keen to appoint her given her dismal Intelligence for a Wizard. But with her ability to patrol the roads constantly chanting ballads of peace from her home country, in a lot of languages and telepathically when needed, she could convince people to renounce any hostile intent while within the confine of the hallowed Foggy Bottom, with a Persuasion check done with advantage (thanks through constant Enhance Ability), adding 1d4+12 (expertise) +5 (CHA) to the roll. That's an average of 34. When she really needed to calm things down, she Wishes for Glibness to ensure rolls between 33-37. It only took a very brief interview for the Council to appoint her...
She's allowed to be followed by a Simulacrum of a Bard 20 (College of Lore) who plays music and stands ready to grant Bardic Inspiration (d12) and cast Guidance (+1d4) on her if she witnesses a difficult situation, like a new person entering the town despite the wall of fog. Consistently reaching 40+ and with a maximum of 57, she is known to invite newcomers for a polite interview in the underground of the House of Liches, the Foggy Bottom's town hall (formerly known as the House of Elders because there was a time, thankfully past, when wizards actually died of old age).
Nobody knows what happens during this interview. No testimony of these interviews was ever possible thanks to Shenta's Alter Memory ability as an Enchanter. All visitors have been able to continue their trip so far, so there is no dark project at hand, but some in Foggy Bottom suspects that, out of an abundance of caution, the Town leaders asks the visitor to submit to a quick Wished Simulacrum spell, while enjoying a superb breakfast, before being welcome to enjoy the commodities of Foggy Bottom. Who know what would happen if the Simulacrum revealed some hostile intention on the part of the visitor?
[BTW, normal voice can be heard in normal conditions at 180m and there is even a recorded case of human voice being intelligible at 17 km (10,5 miles) under ideal acoustic conditions (according to the webpage of the Guiness Book. The Silbo whistled language from the Canary Island can be heard at 5 miles. I found this fact fascinating... especially since it's much farther than 660 ft.]