Hmmmm ... wouldn't a folder synchronization via server like this -->
https://www.dropbox.com/ be a solution?
I imagine if I would have two machines on which I would want to play and if I was working on mods on both machines, then this would be about the first thing I'd set up.
You simply declare a folder on your drive (so in this case the mod folder) as the folder you want to synch with ''others" (your other machine). Whenever you have dropbox running and you are online (which I assume you are, since you are playing with UBIs lovely DRM

) the mod folder is synched with a server repository. If you then move to your other machine it checks for changes on the server and updates.
... hmpf, sounds more complicated then it is. Here, let me make you a diagram.
M(achine)1 [ ] ----- S(erver) [ ] ----- M(achine)2 [ ]
Put a mod (x) in folder on M1
M1 [x] ------ S [ ] ------ M2 [ ]
M1 [x] -(x)-> S [x] ------ M2 [ ]
M1 [x] ------ S [x] ------ M2 [ ]
Go to M2 over holiday
M1 [x] ------ S [x] ------ M2 [?]
M1 [x] ------ S [x] <-(?)- M2 [?]
M1 [x] ------ S [x] -(x)-> M2 [x]
Change mod on M2 (x -> y)
M1 [x] ------ S [x] ------ M2 [y]
M1 [x] ------ S [y] <-(y)- M2 [y]
M1 [x] ------ S [y] ------ M2 [y]
etc.
With Dropbox the first 2 GB are free but I have to admit that I have NO idea how big SH5 mod folders get. I'm one of those that can't play the damn thing. If you've got your own FTP server online there might be open source solutions for this as well.