I have a grandfathered plan from Cricket wireless which gives me 20 gigs of data that is ok to tether. I've never seen that plan so I can't say much about it. The biggest thing is to double check to see if it's ok to tether and what the limit is on "unlimited" there is always a gig limit before they slow you way down.
The one I was looking at for some extra data is from ATT. It's a old plan that was never made popular but it it's a wireless hot spot you plug into your car's OBDII plug. It's called mobley.
https://www.att.com/devices/zte/mobley.html
Now the kicker is if you go on ebay and search mobley, there are adapter plugs you can buy that let you run the hot spot off a USB cable so you can run it in your car off a battery pack or even in your home. The hot spot is only pulling power via the OBDII plug so it doesn't have to be connected to a car and ATT has no idea if it's in a car or sitting in your house or in a tent out in the woods.
You can get up to 3 of these devices on a single plan, each device gets 22 gigs and is $20/month. so you can get 66 gigs of mobile data via a hot spot for $60. The down side is you have to buy the devices and they are $100/each and seem to be hard to find, due to it being a older plan that never gained traction.
The verizon thing looks interesting but usually these "unlimited" plans are capped at 20ish gigs and then they lower your speeds..