OldFatGuy: So if, say GOG's problems are potentially fatal, you/we won't ever know until it happens. You simply can't, from a business perspective, at least it seems to me, put out any kind of "warning" to your current customers that things are going bad because... duh... that will lead to things going bad faster. What I'm trying to say is if you haven't downloaded every game you own on GOG, now is the time to do it. Because if things go sideways, you most likely won't get a notice beforehand and your games will be gone... forever. And even if they were able to give some sort of warning before going out of business, it would by default have to be a short one, and well, guess what's going to happen when every GOG customer tries to download every game after that warning is issued.
If (IF) the company will have to close (for example by saying that they cannot cover their monthly expenses, or whatever other reason), I don't think it would happen so suddenly. Most often retail stores, of any kind, announce a final date on which they will stop functioning, and have serious discount offers until that date, in order to have some last profit and decrease their overall damage.
If that happens, I tell you I will buy hundreds of games at once! I don't buy them now, because I feel better of buying a few each time and playing/finishing them, until I buy something else. But if THAT happens, then yes, I would buy many at once.