wait, are you worried about maybe running out in the future, or have you already been running out?
Leaks are pretty common unfortunately, so if you are already running out, leak testing is you first path.
I found that my usage was a little less than a pound per day when camping in the rocky mountains with some furnace usage each morning. I use a lot less when it's hot enough to skip the furnace. That's without an LP generator though.
So, maybe that's not very helpful for your situation, but well, it's what I've got.