Not-taken-up 748s must be the real bargain, so I expect them to be grabbed soon.
As regards new frames, they must already be offered at rock-bottom prices, and I doubt Boeing is ready to build more just to sell them at a loss. Boeing also has to sell more 777Ws, which are essential to the bottom line.
The MoU with ABC was for upto 20 8F, and ABC is expecting to take 3 frames per year. Plus the small amount of unfilled orders, at 0.5/month rate, as I predicted before, Boeing should be able to keep the 748 production alive until the VC25 coming to production line - the second VC25 probably will be the last 748 ever.
Air China top up, not in the near future, when US Navy is discussing the possibility of base a second carrier in Asia and the presidential election result is unclear.
The one country to save 748 would be Iran, if Boeing is, as reported, in discussion with Iran, then all white tail and the frames in the desert will have no problem to find a new home in very near future, especially they can be delivered much quicker than A380s.
How about long lead items? They must order certain parts well ahead of time to feed expected production during the next years. 0,5 must be the lowest possible rate. Too bad the global cargo outlook is so weak these days. I hope the 747-8 stays alive.
Boeing must have negotiated with all suppliers for 748, and Boeing is happy to pay for all parts at 0.5 rate, even if that means some white tail. They knew the VC-25 is a must, it brings in more marketing benefit and honour than few billion pounds would do.
10 in production line, 18 from ABC (if they really taking all remaining 18 at very low rent from Boeing Finance), should be enough to keep the production line going for at least 4 years. And eventually, the white tails will find home in ABC or Iran.
The next few years, 748 project itself would be a calculated lost, but huge honour with VC-25.