The hollow's eve fest usually has an entry room that is open to the public. A first room that you can only get past if you are signed up for the festival.
I would suggest that caravan's have a way to enter this room (maybe not through portals or flying ships, but maybe if they take the manual journey over to hib).
Secondly, if caravan's can enter this room, i would suggest a feeding trough somewhat like the feeding trough on the barges between riverhaven and lang.
This way, thoes traders attending the fest can have a place to park their caravan without needing to feed it every few minutes.
Of course, if trader logged out, caravan would autostable itself like normal.