Cell Phone Boosters

The last time I was out boondocking, I had trouble getting a strong enough signal on my iphone to enable me to use my iphone as a hotspot so I could connect to the internet with my Mac Book laptop. I had the same problem using my Verizon Mifi hot spot.
I could only get one bar inside the trailer, which was not sufficient to get on the internet, but could get 2 bars outside the trailer. Two bars was enough to establish a connection to the web, albeit pretty slow.
The outdoor temperature was about 45 degrees. The charge cord on my phone was long enough so that I could put my phone outside the RV door, on the step, with the cord plugged into my invertor inside the trailer, with the RV door not fully closed so that the door would not cut the cord. At first, my phone kept shutting off because it was getting too cold for the battery to work. So I put my phone inside a winter glove, on the step, and the phone stayed warm enough to work. Not the best solution but at least it worked.
I have been researching cell phone external antennas, cell phone boosters and the like. However, I am still pretty ignorant.
I would like to purchase something but confused at this time.
I would appreciate it if you guys with cell phone boosters would share your advice and knowledge about these matters.
Thanks!
I could only get one bar inside the trailer, which was not sufficient to get on the internet, but could get 2 bars outside the trailer. Two bars was enough to establish a connection to the web, albeit pretty slow.
The outdoor temperature was about 45 degrees. The charge cord on my phone was long enough so that I could put my phone outside the RV door, on the step, with the cord plugged into my invertor inside the trailer, with the RV door not fully closed so that the door would not cut the cord. At first, my phone kept shutting off because it was getting too cold for the battery to work. So I put my phone inside a winter glove, on the step, and the phone stayed warm enough to work. Not the best solution but at least it worked.
I have been researching cell phone external antennas, cell phone boosters and the like. However, I am still pretty ignorant.

I would like to purchase something but confused at this time.
I would appreciate it if you guys with cell phone boosters would share your advice and knowledge about these matters.
Thanks!