You can fit 4 by putting two benches in a L shape. However, it's tight and the unlucky fella who is sitting closest to the stove is going to feel the heat big time. Technically I am pretty sure you can cram in 5-6 but you wouldn't enjoy it lol

We had 4 large guys guys in the standard (not XL) and had the temp pushing 230-240 and I was the aformentioned unlucky fella who gpt sat in the seat closest to the the stove. . I had to take my icewater soaked towell and drape it over my legs b/c it felt like I might combust at any moment lol.

The clain in take 30 minutes to reach 200 but I swear it was more like 15 minutes. The way I've experienced it is two logs get's you to 180-200 range, when you add a third log, it goes 200+. I know there is an air intake and other mechanisms for controlling the temp but I've never seen it being manipulated whilst the oven was cooking.

It comes down to seating and personal preference. I have 1 bench and one chair.

and we do 4 occasionally. More than 2 and it can be difficult to avoid

bumping into each other. Comfortability is subjective for sure. I have had friends 'freak-out' with just one other person and opt-out of the whole sauna thing. Others: can't get enough and joyfully take their cloths off! I do think there is a minor ramp-up to really enjoying sauna. My wife and I use our sweat tent 4 + times/ week. our tent is on the water so the cold water immersion is almost built it. I can't wait for winter!

I think 3-4 can fit comfortably, depending on the people. Are you looking to get a SweatTent? I have the XL and love how spacious it is!