When I got married, we had our venue for the entire afternoon, until about 6pm-ish. After that, we wandered down to a neaby pub with a large garden, a well-known chain that said on the door it was family friendly.
"The children have to leave by 8pm" we were told, not long after we'd got there but after the first round had been bought. This was the company rule for the chain, not a licensing condition (my husband enquired, using the right terminology, as he works in that industry!) There were 20+ of us, on a Monday night, pretty much the only people in the place, but the children have to be gone by 8pm...
So we moved to the pub just down the road a bit. A proper drinker's pub, an old-fashioned boozer. We asked the landlord if he minded having a big group of us turn up, including children, taking over pretty much his entire beer garden. He was delighted. A while later, when my little bro got hungry, we asked if it was OK if we went round to the chippy and got some chips for the children to eat in the garden (the pub didn't do food) - the poor landlord looked at us like we were mad, really 'why would I mind, it keeps a big group of people in my pub on a Monday night!' It was great because they were happy to have us and we were delighted to give them the custom - and it was almost even better that it was probably the last pub in town you would normally have considered walking in to!