Rive Gauche and Saint Jacques
Hotel Rive Gauche On the river and just a ~8 minute walk into the center of Joigny. We stayed here when first visiting and highly recommend this hotel Rates from 98 EUR https://hotel-le-rive-gauche.fr/en-hotel-bourgogne-contenu2-notre-hotel Cote Saint Jacques The nicest hotel in the area with a Michelin starred restaurant on-site. We have not stayed here but are told that it is fantastic Rooms from 290 EUR (or 190 EUR for their sister property Maison de Famille) https://www.cotesaintjacques.com/en/page/5-star-hotel-burgundy.3.html
Airbnb, VRBO, etc.
For larger groups who also want their own space there are many reasonable rental options available on Airbnb or VRBO. For those of you with kids there is a small holiday village with basic accommodation and activities in the next village over (within a 15 minute drive of the wedding venue). See the website for more info: http://www.valleedelyonne.com/