Since the rescue bit worked so well, for a long time, the easy route would be to purchase another one and have it for "the next time".
Aside from that, I'd drill the broken screw out and heli-coil the hole or just tap for the next larger fastener, 10 or 12-32, or use the plastic insert idea.
Drilling the hole oversize, tapping that hole to insert a larger bolt and then drill and tap the bolt for the screw seems like a lot more work.
But we all get cheap and over analyze a simple problem now and then...
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