Re: Using a MiFi in a cabin with my Apple TV. is there a better way?
I know that the original post is pretty old and not sure this is still an issue, but figured that someone else might benefit from a solution.
I also have a MiFi, which I use primarily when traveling, but also as a backup to my cable Internet service.
I suggest you purchase a small portable wifi travel router which can be setup as a wifi client. I use a USB powered Asus (WLAN-330gE) for this task. The Asus gets setup as a client to the MiFi. The Ethernet cable of the Asus is then connected to the Express. In this way, anything connecting to the Express will be on a common network. The Express uses the MiFi (via client device) to connect to the internet. The only device that has to connect to the MiFI is the Asus (client device). I would further recommend that you put the MiFi-to-client on one wifi channel (like channel 1), and use a different wifi channel on the Express (like channel 11). Since the Asus can be powered via USB, it can be connected directly to the USB port on the Express. The Express may complain about the double NAT, but you can just ignore the warning. Another benefit, the MiFi can be placed wherever it receives the best cellular signal, it doesn't have to be located near any of the other gear.
In my use case, I route the Ethernet from the Asus directly to the WAN port of my main router when my cable service goes down.
Hope this helps.