I can run my kettle at low and slow temps for quite a while using the standard weber charcoal baskets. I have run it for 8-9 hours before with no problem. I have several videos of that process... I cooked ribs one time and a boston butt on the kettle like this. I did not lite all the charcoal at once... I created a minion method burn in the baskets. There are lots of different ways documented on this site to do long low and slow burns on a weber kettle...
Kamado Joe Jr. ° Kamado Joe Big Joe ° Kamado Joe Classic ° Old Country BBQ Pits Brazos Offset
UDS ° Traeger Lil' Texas Elite