Unless I'm misreading, it sounds like the HW drought is effectively that for most of the North American continent, hardly a single drop of rain falls for the duration of the drought. Perhaps that's what needs to be modified, maybe more along the lines of the dry spell we got in the midwest last year (2012, in case this post lasts into posterity
). We got rain, just not that much. Sure I thought it was kind of nice that I didn't need to mow my lawn for all of July, but it did suck not being able to find a decent ear of corn.
So, to bring this back to the game, rather than the drought starving out 75%(?), maybe it starves a "mere" 25%. A shortage here, a shortage there, insufficient distribution of goods to areas, etc. All these and I'm sure things I'm not thinking of here, would contribute to the ones who do die off.
Another thought that comes to mind is the rampant disease mentioned (in the v1 timeline at least). As I recall, it says by the time all that had run its course, around 50% of the global population had been wiped out. I'd say that should not be applied equally. Life ain't fair; some places will handle it better than others. Places like the US, Canada, the UK, and so on, will have stocks of medicines to lower the death rates in their areas, while some other nations will have no access to these life saving medicines, due to the nearly nonexistent shipping industry of the time. So, my thought is that the first world countries might have a lower death rate from the plagues ... maybe 40 or even 30%, while poorer nations may see death rates of 70% or even higher. Without looking it up, I seem to recall around 2000 the US had a population of something like 270-280 million. 280 million - 40% death rate = 168 million. Then with my proposed lowered starvation of 25%, that brings us down to 126 million. That should be enough of a population base for an effective, if not rapid, recovery.
Of course, food production will be a priority in the recovery. Then, medical care would certainly be something people would think of. During the worst, many people working in the fields to get some food to stay alive are obviously not farmers by trade. As the food situation begins to stabilize, the doctors in the fields will get back to their hospitals and clinics once the opportunity arises. Similar for those in technical trades. Getting the machines back up and running will help move things along.
Of course, none of this will happen overnight. Getting completely back to the prewar lifestyle may take a generation, but people will want to get back to it. Also, in the T2K universe, we'll still have "the Evil Soviet Empire" to worry about, so there will be a push to get back to a point where we can face them again if needed, because we know they'll be doing the same thing regarding us.
That said, let me also say I'm not claiming to be any kind of expert on these matters. So, I might be way off base; I'm just speculating in a lot of what I said.
I also think the writers at GDW back in 87 were largely speculating as well. And, they didn't have the access to information we have here a quarter century later. And, they had deadlines to meet. So, Howling Wilderness may be crap, but maybe, just maybe, parts of it can be 'fixed' so it makes a more realistic picture of things, and still provides the recovery that leads into the 2300 timeline.