In a world where the Napoleonic Wars go roughly the same, with the major exception being that the HRE is never dissolved, is it plausible that the institution is used as a vehicle for German nationalism by Bismarck (or an equivalent savvy politician) in the same way that the various historical successor organizations, such as the German Confederation and North German Confederation, were historically? Would there be an opportunity for the HRE to federalize?
I suspect that would be the case, yes.