Getting lost is a way to find yourself.
I'm doing 2 sleeping bags, both fleece bags (50 d rating). Originally was just doing one, but I was cold under 20 (wearing my thermals +whatever necessary). Then started putting the fleece bag in my synthetic bag which was beyond warm, but too heavy. So now I'm doing 2 fleece which has tested great so far, but I'm going to keep testing.
Also sending one back when warms up, and swapping out when 1st one needs replacement.
The only thing about fleece is that it's heavy and doesn't pack small.
I personally like the 2 bag option with fewer clothes best.
If you're hiking, you won't need a lot of warm clothes. If you're willing to go from hiking directly to your bag then you'd save weight carrying 2 bags and fewer clothes (if the bags are top-tier down bags).
But, if you like to stop early and hang out or for whatever reason have a hard time going directly into your bag then you obviously need clothing - in which case you don't need 2 bags.
The formula I have seen is [x -(70 - y)/2 = z] provides this:
X=45 and Y=55: 45-(70-55)/2=15
If it do'nt eat you or kill you it makes you stronger
'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton