Data plans can be expensive but if you keep an eye out for sales it is pretty cheap.
We were watching sales last year as we have 6 phones on our account as we switched from unlimited data to the shared plan. We went to 20 gigs and it suited is fine using our phones for hot spots( iPhone 6 Plus and other iPhone models). We were watching sales and we happened to see the ad for if you call in and speak to a rep they will double your monthly data for nothing.
We called in and they doubled it. Took about 10 minutes and it is for life.
When we travel we maybe go through 10 gigs. Sometimes more because the 2 kiddos use up a lot. But the other phones are all adults and don't use the Internet very often.
I use the hotspot all the time at work to do my bills and banking online because I'm not always home and have a heroic work schedule. Never had an issue.
But keep an eye out for those deals.
The last one we saw was for they will give you half more data a month for free. So if you had 10 they will give you an extra 5.