Right so the other day, I somehow managed to delete everything I’d done in the game up till now! I restored ‘part’ of it somehow but my boyfriend and I would like to understand what happened.
Basically what happened was my boyfriend was playing the game via the family sharing on Steam - he moved some characters from his PC to the laptop via cloud saving (meaning he enabled cloud saving in the game plus in the Steam options) to his ‘own’ Steam account… After a while, I wanted to play on my own account and took over on the laptop… Everything was working fine until I closed down the laptop for a while and when we opened it again, it had deleted EVERYthing 
My boyfriend tried looking for the local files which was completely empty, he tried logging into his Steam acc and still nothing… We tried looking up on the interwebs how to restore but no ‘easy’ solutions except restoring an older version of my entire computer and I just couldn’t be bothered so I started over entirely… After 16 levels, we realised we might as well move the characters that my boyfriend has on our PC so I at least didn’t start from absolute scratch… So we went on Steam on the PC on my account, enabled cloud saving both in Steam and the game itself… We log off Steam on the PC and log on on the laptop - great, we have now moved all my boyfriend’s characters (that he normally keeps offline to keep our characters seperate prior to family sharing in Steam being a thing) but hey what’s that now? My old characters (only 1 of them) from before everything was removed, is suddenly on the character list! So basically I ended up only losing old characters plus my stash, upgrading with all my geeky boyfriend’s level 80s+ characters and his full stash!
We have now disabled cloud save on Steam and in the game, on both my own Steam account as well as my boyfriend’s account! lol
What we’re wondering is what will happen in the future if my boyfriend wants to play from his own Steam account, via family sharing, but on my laptop? Can he safely enable any sort of cloud save (Steam, the game or both) without somehow removing all my files again? Should we always just disable the game’s cloud save while enabling Steam and we should be fine, or how does the cloud save functions in the game vs Steam work?? 
Sorry for the long post! Hope someone can make us understand what goes on
Cloud saving just seems to screw up for some reason so best to stick with local saves and never turn cloud saving on again. It’s easy to back up the local save folder and then just put it on to another machine.
Does all cloud save screw up though? I’m not sure if I remember correctly, but the cloud save function in the game itself is fairly new right? Because we used to use the Steam cloud save sometimes (both in this and other games) and it’s been working as intended (e.g. if I played online last, and my boyfriend then logs on on the PC, it’ll say there’s conflicting files like the Steam cloud save is supposed to - where as the game’s cloud save just kinda seems to overwrite in whatever messed up way?)
Also where is it we’re supposed to locate the files? We googled and someone also tried to tell us in a Steam forum post how to locate them but we just cannot find them on my laptop for some reason - at least my boyfriend says they’re not where they’re “supposed” to be according to the googling he did yesterday? 
Cloud saving’s been in the game from the beginning as far as I know.
Local saves should be in C:\My Documents\My Games\Grim Dawn\save
That’s the default, but if you put My Documents somewhere else then you’ll need to find it.
Or
steam\userdata*your number*\219990\remote for the cloud saves
never ever had a problem with it
same, but then I never used it 
One thing to keep in mind is that local and cloud save their files in different dirs and on top of the cloud save setting in Steam there also is a setting in GD which I believe affects which save dir is used.
So maybe you switching back and forth just means you do not see some of your chars rather than that your chars were deleted.
I certainly would be surprised if anything actually got deleted. The worst I have seen of cloud save is that it reset a char to level 1, no quests, so basically a new char (and that requires meddling with the save files outside GD, which sometimes ‘surprises’ cloud save and leads to that reaction).
A char never was actually deleted completely.