So what's a good number of armies to abandon on the Insane Challenge?

I think a total of 100 armies abandoned for one territory might have been a bit much...
but it was Canada N, and the AI was willing to sacrifice 10 to 25 armies per turn...
much more than I was going to be able to muster.
( I had concentrated on accumulating as many bonuses as possible, knowing that I'd probably run into the brick wall of the AI once I took Canada...
(20 of my armies were abandoned x 500% = 100 total.)

So basically you wonder how to win the Insane challenge? It is YouTube videos on how to do it, as well as several forum posts.

I would like to know how... but I know many players better than I who have not beaten it,
so I'm not feeling quite that impotent yet...

So I figured I would ask about the newest and most unfamiliar part of the Insane Challenge. :)

Watch out for the AIs coming from Scandinavia S, Canada S and Australia S. None of the rest are all that harmful, if you get there in time. I know this from several recent failed attempts.

Svalbard S was always the first territory I abandoned. If you're lucky the AI will just build up a stack behind it and won't break through until you have enough income to deal with it.

Not sure what the optimal number troops to abandon would be. I think I used 15-20 but I can't find the save file so I can't say for sure.

Thanks for all of the good information. :)