Sleep in his tent. Wife will enjoy having her tent to herself.
Line up your bag with the exit door.
Locking someone in a flammable tent in a flood zone, does not sound like a hot idea.
As a family, we had to make peace with the fact that none of this was really safe. We can't avoid water, and nearly all lakes and streams are thick green 0 vis water. If the kids dont pop right back up on their own after they jump in, theres nothing we can do.
One niece always has her little backpacking backpack. Mountain hardware IIRC, she wont go anywhere back country without it. A simple GPS pog made it easy to track her. Dog has another.
Sure, sleeping across the doorway is a good idea. Putting your bag in the doorway, I like that too. But no, wife will not likely enjoy a tent to herself. If they have a child together that suffers this condition, she likely wants to be right there with him and wont want to trust anyone else to be completely in charge.
If you dont bring flame into your tent and you put out your fire properly before turning in, it is highly unlikely it will catch fire unless there is some other local issue at hand. And if there is some sort of local issue at hand that could cause your tent to catch fire - like ash or fire falling from the sky - consider the idea you shouldnt camp there
Also, dont tent camp in a dry river bed.
You are right, none of this is safe, but risks can be mitigated.
Murky green river water...should you be in it? If you decide to let your kids in, hoping they pop back up os not a strategy. There is something you can do - you go and be not far down river from them, so you have a chance to stop them being carried downstream, they bump into your legs and you pull them up. Or string a rope across the river.
Yes it's dangerous, but I disagree with your cavalier attitude that nothing can be done. Maybe not after the fact, but taking precautions ahead of time...a stitch in time saves nine
