If you are going to a bandwidth constrained place and are miles from anywhere then taking as much of what you need with you would be a good start. I know it sounds obvious but I remember my days of helping with peoples home computers when I had broadband and they were still on dial up.
You mention Windows 7 so I assume the licenses are already paid for and the specs of the current machines has been checked and are more than capable of Windows 7. Otherwise I'd mention checking this first and if required investing in upgrades or going to a more light weight OS. Also, Windows 7? I appreciate it is nicer than 8 however it has 3 years fewer support. To me an you this might be ok as we likely change our computers more often, but possibly just possibly here OS longevity should outweigh the benefits of sticking to Windows 7. Don't forget to get the drivers downloaded in advance.
before you go make an up to date Windows 7 image (including all current updates), instlal whatever you might want on it then shrink the size of the image and clonezilla the machine.
When you are there image that back to one computer install anything remaining then and sysprep it. Make an image from that,
Bung out the image from a clonezilla server machine and voilla.. Go round put in keys and activate and you are out of there other than the bits that just don't sysprep well like Kaspersky if you are using it.