Kim, the only real answer, if internet is necessary, is to use MiFi devices. These provide a cellular router inside your TT and give you access to the internet via cellular broadband.
The general category is called a Mifi - but you'll see Verizon call theirs a Jetpack and some times ATT calls them a broadband datacard. But it's all the same.
Because no one provider covers every place you might travel it's helpful to have more than one account. We use ATT and Verizon. About 80% of the places we visit have good service on either one of those two. But in the other 20% of places only one of the two is practical for use.
The next problem is getting enough high speed data to meet your needs. For general office use you probably will be fine with the options from the major carriers. Please know that EVERY carrier offers "unlimited" data plans that are extremely limited. How can that be? Well, they will let you use all the data you want every month with no extra charge - but they limit the high speed data that you can use. Most unlimited plans offer 22gigs of on phone data and 15 gigs of Mifi device data. When you use up the high speed data they drop the speed to 2G speeds - really it's dial-up speeds.
Most work uses don't use a ton of data. But video or TV streaming use a tremendous amount.
You can bypass all of the MiFi/Jetpack business and use a cell phone as a hotspot. But this isn't as convenient or speedy as using a MiFi most of the time.
Also, with the Mifi it's a router and you can connect multiple devices - your phone, your tablet, your laptop, etc and you will have a private network connection inside your TT just like at home.
From there there are a great many more things you can do. But it will depend on what your deeds are and how much you want to spend.
We have a WiFi Ranger which consists of a network router that uses both any available Wifi and rebroadcasts it into the private RV network. And, MiFi devices connect to this router via USB or Ethernet and you can set up auto load balancing between campground wifi and two or more MiFi devices and let the WiFi Ranger router switch between them all seamlessly as needed.
Also, there are Cellular Boosters that can amplify a weak cell signal in remote areas to make the broadband more usable.
And beyond that there are professional devices that can combine all of these things into one rooftop device.
I recommend people join www.rvmobileinternet.com
. It is a website that keeps up with all of these things. Tests all the equipment and antennas. They tell you what dataplans are best, etc. It's free to visit and you'll see about 1/2 of the content. If you become a paying member you get access to it all. There's a ton there and it's updated almost daily.
Here's what we have:
Wifi Ranger GoAC Router
Wifi Ranger Elite Rooftop "booster'
WeBoost Drive 4G-X Cellular Booster with rooftop antenna
Verizon 7730L 2.4/5 ghz Jetpack
ATT Nighthawlk 2.4/5 ghz Broadband router
And, we have two things that are just not available any more that we established a couple of years ago - ATT Connected Car totally really unlimited high speed dataplan for $22 a month and a Verizon Grandfathered totally Unlimited Dataplan for $34 a month.
Because our plans are totally highspeed unlimited we use it for streaming all our TV and we use between 200 and 350 gigs of data per month when we are on the road.
Best of luck to you. It's a huge topic and you have a great deal to learn about mobile internet in your travel trailer.