Hi Ed,
Years ago, I used hot hide glue a little for case work, but certainly not enough to qualify as truly experienced. So I don't really have much to offer in the way of specific practical advice. But, you asked about 18th century practice, which I think is an interesting question.
There's not much detailed discussion of the use of glue in 18th century sources, but I believe we can extrapolate some general possible strategies based on a number of other sources. Specifically, I've re-looked at Moxon, a 1734 Builder's Dictionary, Nicholson (1831) and Holtzapffel (1843). Not to mention a couple of 20th century sources. I'd be happy to discuss these in more detail if folks are interested, but think it would be quite tedious in the present message.
In brief, I believe 18th century cabinet-makers likely used some combination of three related strategies to aid in gluing up case-work.
One strategy may well have been to briefly ramp up the temperature of the glue just prior to the glue-up. Hide glue can be compromised if this is repeated too often or the temperature taken too high (over 180ºf), but a sparing and judicious use of this strategy would not only allow the glue to penetrate better (especially with denser timbers), but would buy some time before it cools too much.
On a related note, I believe they may have pre-heated the joinery parts, when possible, toward the same end. Nicholson specifically mentions this when dealing with longer edge joints. Also, it seems well established that a traditional method of laying veneer on larger surfaces was to pre-heat the surface being veneered as well as the caul which was to be used in providing uniform pressure on the veneer. This actually allowed the glue to re-liquify and penetrate/move as required when the slightly convexly bowed battens were clamped down on the caul. Apparently, the caul was often pre-heated over a shavings blaze, especially when other sources of heat may not have been in use. I'm also thinking that they may have moved glue-ups closer to a stove or fireplace during the winter months, in order to take advantage of the additional heat.
The third strategy has to do with planning and preparation. One aspect of this may well have been to do glue-up in smaller increments if at all possible. Nicholson seems to hint at this when discussing mortise and tenon joints. However, that is not often possible, in which case, the idea is to make sure everything needed is at hand prior to brushing on the glue, even rehearsing if at all possible with more elaborate glue-ups. Plus, recruit additional hands if available. Nicholson mentions that longer rubbed joint glue-ups would benefit by having at least three people at the task - one on each end and one in the middle.
Eighteenth-century cabinet-makers obviously found a way to do such glue-ups successfully, so I see no reason someone today couldn't pull it off if that is their intent. With a little practice, it may not be any more stressful than similar glue-ups with aliphatic resin based glues.
Hoping to be of a little practical help, I'm including a link to a small pdf file of a couple of short chapters about glue usage from an industrial arts textbook, _Instructional Units in Hand Woodwork_, by Tustison and Brown (1930):
https://drive.google.com/file/d/0B5YwO2tVTpdcQjVLWWlhNXJGTmM/view?usp=sharing
Hope this has been of some interest.
Don McConnell
Eureka Springs, AR