I used an IP camera for my first two, using a baby monitor like yours for the third. I prefer the non-IP monitor too. All the reasons you list, plus reliability. I don’t have to worry about my baby monitor crashing in the middle of the night like I did with the IP cam app.

Talk with the staff or check their web page. They probably have open games or adventurers league games you could join.

I think it’s a matter of in what context the quantum ogre is used as well.

Combat is complex to balance in 5e, so encounter design takes up significant prep time. It makes sense the user a quantum ogre where the players are arbitrarily picking between rooms A and B in a dungeon. They have a fight, then the DM has time to prep a puzzle or another combat in the unused room for next week.

The poster you’re replying to shows when quantum ogres are bad. World building at a basic level isn’t a heavy lift, so limited prep work is wasted by fleshing out both locations. And your players won’t out level a city or NPC like they will a combat. So you can always come back to that unused location later with minimal additional work.