For my purposes, I could work with speeds as low as 1.5 mbps download and I saw as high as 40-50 mbps. It all depended on where we were and how many other people there were. I also put “cell service” as my very #1 priority when looking at camp spots. It was rare, but I had to drive to cell service a couple of times or use/pay for campground wifi.
My family used somewhere between 100gb-400gb in a month. Family of 4. My working took about 1gb per day.
My cellular plans are unicorns from 2015/2016 and aren’t available any longer. I didn’t experience throttling but overloaded cell towers were a real problem at times, especially in snowbirding areas. I carried AT&T and Verizon and always debated a T-Mobile plan as a 3rd provider. Having multiple providers was paramount to staying online. My cellular bills (3 phones paid in full and 2 hotspots) ran north of $300/month.
The most effective piece of equipment was my $50-ish Netgear MIMO antenna. It plugged straight into the hotspot devices:
But there were times my WeBoost 4G Drive X with upgrades OTR antenna helped. I had a network router/wifi booster (which I almost never used that booster capability), the pair of hotspots, MIMO antenna that I mentioned above, and the cell booster:
More recently, SpaceX’s Starlink has become a viable option. While roaming is not officially supported, more and more people are finding that they don’t have to play games with their service address and are able to venture further and further from their service address location. The speeds are typically faster than cellular service on download (from 20-100+ Mb) and about par for upload speeds (4-8 Mb). This is truly turning out to be amazing for the folks who are traveling with it.
For those who NEED to be online, I highly recommend a membership to RVMobileInternet.com. It’s gotten expensive (maybe a little too much so) but they keep their finger on the pulse of cellular offerings for RVers.