Munich beer garden - Unterhaching

Many bierhalls (including Hofbrauhas) don’t take reservations for groups smaller than 6. As a couple, we’ve been instructed to just find open spots at tables and join another group. It’s part of the fun!

We visited Hofbrauhaus during lunch on a weekday and it was dead. We just wandered around looking at the massive rooms (after rooms). When we returned for dinner it was hopping. Polka band, chanting crowd. Exactly what you envision. I’m not sure I would call it a carnival atmosphere. And staff were taming down some of the patrons. But it was fun. So timing is everything. Our visit was in the summer, so it being in October may be a bit different.

I would watch some videos of Munich bierhalls and see which appeal to you. You can always pop into a few and check them out.

We were there last year for Oktoberfest. Here is the official website: https://www.oktoberfest.de/en#:~:text=The%20189th%20Oktoberfest%20will%20be,21%20to%20October%206%2C%202024.
Last year, you needed a minimum of 10 people to make a reservation and you needed to prepay a certain amount to register (it explains all of this on the website.) We were only 5 people and never made reservations. We were able to get in to (eventually) each tent we wanted to visit mainly because we went a bit early. In the website there is a "barometer" page where it lists the busy and less busy times/days. You can use that as your guide if you are only going for a day trip.
As for tents, they are all very different in terms of atmosphere (though they all offer beer, chicken and pretzels.) Do some research to find out which tents have the atmosphere you are looking for during your visit. This research makes the visit more fun!
Hope you have fun!

Thank you

Oktoberfest tents and Munich beer gardens are two different things. If you stopped at Hofbrau on your walk I would pick a different beer garden or restaurant for dinner. Going to the Hofbrau during Oktoberfest in not the same experience as going to the Oktoberfest fair grounds.