Big tents are great in theory. However, you don’t always have the right space to put them in a campsite. Keep that in mind because the large footprints limits locations to some campsite I would like to go to.
I have an instant cabin tent that solved my space issue. It’s a 6 person Coleman. Not too expensive and has held up
6 person at least. Room for sleeping setups, and some gear. You don’t want to be right up against the tent wall. Also look at the center standing height, for the tents you look at they will tell you.
Ex: I have ozark trail 6 person instant up dark rest tent. For me alone, it’s great. I can sleep myself and wife if needed. I would still want bigger.
Coleman instant cabin tent, 6 person, a bit more room than OT, and taller in center. I personally like OT more for the features, but just one example of size being different among brands for 6 person.
But ya it’ll depend on your sleeping setups. If you are trying to do a single queen size mattress, 2 cots / pads, etc.
When you aren’t worried about weight and size as much, you can be more comfortable. 4 person will get it done, 6 person probably sweet spot, anything more and you’d be just looking for more room. It can be good to have a lot of room when rainy / buggy / something keeping you in tent for some reason.
I've got a similar issue. I've got 2-3 tents that I've narrowed down to but haven't pulled the trigger. For size, it really depends on if you want lounging space inside. A 3-4 person tent is good for two adults with gear inside. If you want to set up chairs inside then a 6 person would be better. With a 4yr old you might even be able to get away with a 4 person but a 6 person would allow for growth. Coleman and Kelty have a lot of nice tents that would be fine for what you want. A Skydome with the screen room has the vestibule for a reasonable price. Not to mention being a darkroom tent so you're not having to wake up at first light. Something like the Coleman Skylodge would allow you to walk around inside. If you want to use cots then bigger might be better. I went solo camping with a 4per dome and my cot took up most of the space. There's no chance to fit a second one in there for sure.
PinkGuava420
