I was always under the impression that there is a requirement to carry topo charts of the route even when flying IFR.
Maybe this has changed but when I was flying for the airlines we always had topo charts in the library.
At the last count we had 8 Aerad binders covering northern and southern Europe behind the 1st pax seat in the Citation.
Damned if I'd know where we'd fit the half-mils too, not that they'd be any good at IFR levels be it inside or outside CAS!