Thanks for the quick replies.

I think I should be fine. I honestly don't have a good idea of what a 70lb bag feels like, which is why I have the concern. My guess is that its currently around 50-60-ish lb.

I could buy a scale, but I need it so rarely, it didn't make sense to me. Maybe I should pick one up.

Worst case, I can easily break out/ redistribute to make 2 checked bags. I'm using a huge Rimowa (29" I think) that is essentially swallowing another bag (that I packed just in case). Easy enough, but mentally kind of dumb to me. One bag @ 80lb or two bags @ 40lb seems the same to me. If anything, one bag seems easier.