Yeah, for my trivia you're definitely welcome to bring a team of up to 8 ppl, and if it's a couple more occasionally then no worries. I want people to have a great time, and I honestly think that once you get above about 6 people it actually makes it harder to come to a decision on many of the answers, plus there's always at least one person with the dreaded "I said that!"
It needs to be a fun game, and obviously I immediately stomp out something cheating if I see it, but I'm not gonna stop your 2 friends who want to join (and push the team over the limit) on a night. It can still be a great and fair trivia without me being ridiculously rigid on rules. Check it out some time!