I think your idea for a sequel to the original Thing is a good one. Certainly, it would have made a better TV series than "War of the Worlds" did: At least with the Thing, they could have claimed a cover up of the initial encounter at the arctic base, and NOT have to say "Oh, everyone just forgot about the invasion of '53..." What a bunch of crap THAT was!

Or maybe this time, the ship doesn't land in the arctic... maybe it comes down in the everglades... It still crashes (all we'd see of it this time is that damned fin slowly sinking into the mud...) but the crew begins to grow an army...