Happened to me once... sometimes those things swell up in the cold... luckily mine was close to the end. Well, personally I'd take the other bar end off and stick a high volume blow gun of a compressor in the other end and watch it fly. But I agree, a hanger would be a wise choice; that or something larger and more rigid.
here's a link to the Ron Ayers microfiche for the assembly: http://fiche.ronayers.com/Index.cfm...roupID/359322/Group/HANDLEBAR_(WITH_COWLING)_
your S model has clip-ons, right? the nut will be floating around inside the bar, and with any luck should drop out once you extract the rubber expander. have you tried reinserting just the bolt with the bike tipped towards that side, to try to 'catch' the threads of the nut behind the expander - sometimes they stay more or less in position, sometimes they drop deep into the bar.