I just use my iPad Mini Retina with LTE.

I have the T-Mobile Simple Choice plan, which gets me 1 GB of LTE for $10 a month and unlimited international data roaming. Speed when roaming is only 128kbps but it's good enough for using Google Maps.

And I can tether my iPhone to it so I kept my iPad in my bag and used my iPhone to use Google Maps.

When I use in the US, I can tether to my iPad as well and I've used prepaid SIMs in Italy and France and tethered in those countries as well.

Best thing is that iPad has the latest LTE radios for networks worldwide and it gets great battery life, so better on both scores than any dedicated Mifi device.