WoW Herb, That was way more than even I expected. You deserve a dollar for every word in that posting, lol.
I would like to add that doubling voltage on an existing line, expecially in the north is very likely a no go.
I am thinking of insulation combined with ice load on the cables, is a condition waiting for a power outage. Similar could apply to adding parallel cable to an existing tower. Towers are designed to carry the weight of cables at the time of construction. Adding weight afterwards, with ice and wind conditions means a likely tower collapse.
Any how folks, you got a cheap education re northern power lines. Baravo to Herb.