This journey I've been on has tested the fringe locations. With my setup I'll link below I have not been without Internet since it was installed in Nov 2018. I have not needed nor have I used the Websoost 4G-X that's installed and I also carry a Weboost RV 65 I'm trying to sell as it has not been needed either.
What I have and use for primary:
Pepwave BR1 MK2 LTE-A Router (this allows for 2 x Cellular SIMs and does WiFi 2.4 and 5 Ghz)
Set up a fast and affordable cellular network for offices, job sites or vehicles by using this Pepwave MAX mobile router that has an embedded Cat6 LTE modem.
5gstore.com
Panorama 5-in-1 antenna which I recommend simply mounting on the top of your front air conditioner cover. Easy mount and highest location, it works great.
Panorama Low Profile LTE/GPS/WiFi Dome Antenna
These are picks as of Nov 2018!!! As of this writing Jan 2020 I have no need to upgrade anything, it works well.
To consider:
MAX Multi-Cellular Router > Peplink
Give your passengers fast, reliable WiFi hotspots with the compact Pepwave MAX Transit and Transit Duo Router available with fast shipping from 5Gstore.
5gstore.com
Another site to review products and prices:
Home - LivinLite.net which their store goes to
MobileMusthave.com - LTE Routers, 4G/5G ready, Antennas, Cables and Accessories
More expensive is the Cradlepoint lineup but has the only CAT 18 modem unit that I know of as of this writing in a product like this (Verizon 8800L is CAT 18 as well).
cradlepoint.com
If Sprint is ever an option then you need to make sure the unit is compatible, I think only CAT 6 modems work with Sprint right now. I do use Sprint as I have their hotspot plan and sometimes it is faster by 99% of the time AT&T is my winning option. I'm fortunate to have the Mobley plan. You could try to get the Connected Car plan but it has risk, most I know of are using it fine.
I like Pepwave as it's easy to use and has a new feature called "Enforced TTL" which helps us hide that we are using a hotspot and cellular providers can slow you down if using a hotspot vs. a phone so it's tricking the system. It's helped me quite it a bit as far as I can tell by getting great speeds on the Mobley I didn't get in the past.
Again, I suggest call 5GStore.com and talk to them and get other opinions. I also welcome other opinions from anyone on this site that wants to chime in.
Just realize, this tech evolves fast, this may be something you'll want to change out every 2-3 years. We have a potential Satellite based Internet system coming in a year by Elon Musk, 5G is coming but I think it's marketing buzz right now with cellular companies using the 5G name when it's not really 5G such as AT&T uses "5G Extended" which is misleading. Marketing nonsense.