Gina when we first got our AT&T air card I bought an antenna to stick on the window but decided since only part of our house had a metal roof it wasn't worth the hassle, but it did help. Instead I use a hub which I happen to have and stick the air-card in the hub which sits in the window and I get better reception. Metal roofs or metal trailers definitely are not 'user friendly' when it comes to using an air card, though oddly enough I have no problem in the car if in a good reception area. You could try an antenna.
I am impressed Verizon let you discontinue service for a period of time, I thought they locked you into a 2 year contract time like AT&T.
Something to note about air card service from these companies, if you cross over the border, as in going to Canada, and use it, it will cost big bucks, which is noted in the small print. Living in the NW I barely think of going to Canada as 'international travel' and when we were in BC purchasing our
Escape in March I went on line while waiting in long border lines - it was a very expensive lesson in forgetfulness, stupidity and paying attention to the fine print.
Beware of borders with that type of service!