I understand that taking away the parts that fail under subzero conditions resolves the coldbug issue in this way that there's a big difference between 65nm (with the failing parts) and 45nm (without ...), hence moving coldbug from around -10°C to -196°C and maybe even lower, but I fail to see what this has to do with the 'lower HT link on 65nm' suggestion.
As told, the HT link helps in preventing the CPU from coldbugging as follows(*): the lower the HT link, the lower the coldbug. If this could be translated in a 'coldbug' function, by which I mean that the coldbug is higher if the HT link is higher, we could conclude that the HT link is one of the factors which play a role in the coldbug prevention scheme. At the moment I have no view on how different the two cores are in terms of design, so I might be missing essential information here, but if the HT link is indeed one of the factors that helps decreasing the coldbug in the 45nm design, why wouldn't it help in the 65nm design? It might not help much, but as we all know -50°C is much better than -10°C. The coldbug won't be removed by using a low HT link frequency, but it might help decreasing it just a tad.
(*): This is a rather delicate assumption I make here. I see the HT link 'trick' as scalable, in other words 1GHz gives a lower coldbug than 1.2GHz, which gives a lower coldbug than 1.4GHz and so on. If that is not the case, and thus the HT link 'trick' only works when it's clocked at 1GHz, the following line of thoughts is not applicable anymore.
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