Yea, mobile hotspots will be a power drainer. When you are accessing high speed Internet, that is a constant microwave transmission both ways and would probably recommend a nuclear power pack! But, should be usable for a short term. That is actually what
they are designed for but people lose track of time when on the Internet and will see/hear a warning of the power drain.
As for the JetPack from Verizon, it is the only thing they have for connecting devices that do not have LTE. Works with anything that has a WiFi adapter just about. Apple devices are better engineered because they have been ahead of the game for some time.
Those things can hook up with a rock, practically. Android devices have had tethering but only a few. You have to check around the phone models that actually support that. Usually Google Certified devices will have it.
At least the people here are asking questions before jumping into getting one and finding out the hard way. These Surface tablets have proven to be particular and don't like most. I figured that both Verizon and T-Mobile tested the Surface 3 which has
the same adapter with their own devices because they are on cue to selling the LTE models when come out (some this century, I think). Microsoft will be selling the unlocked model on their web site.