Use a signal applifier like a Wilson and make sure you have a very new cellphone with highly rated cell phone radios and can use it as a hotspot. Samsung Note 10s or S10s are some of the best. I’m sure the S20s and Note 20s will also be good.
There's not much difference in the new phones and reception..Actually the LG-40 has one of the best radios around for reception..It used to be Motorola phones were far superior,Noticeably..Samsungs were terrible and Iphones not to bad..
I used to root cell phones and put an operating system of my choice on them including the radio..Now,with the new phones,there is no need to root anymore..I went with Google Pixel phones without all the pre-installed malware others like Samesung and Verizon phones come with you can't delete..Google made it where there is no bloatware with there phones...Stock Android..Period..
I used to be really into cell phones and reception being way back in these Idaho mountains..I have a Yagi directional cell antenna and a high db rooftop antenna..A good high db external antenna is very important for reception as is something like my 2 Wilson 45 DB amps that can be piggy backed to work together for a higher db..
Cell phone reception isn't determined by the bars on the top,some are very inaccurate..The real reception is in setting under about phone, where it list the correct reception in db.. The lower the number the better reception you are receiving.. -70 db is pretty good while -100 is getting pretty weak and anything past -110 to -120 or so, is no reception at all..
If I was wanting to work out of an RV and needed cell reception I would get:
1-A high gain external antenna
2-A booster like a Wilson booster/there cradle works okay but not near as well as there larger 45 DB types..A cradle is about 1/2 that.
3-A Yagi antenna or a directional high gain antenna for when your in place for a while is better than the smaller antennas..
4-A MiFi so everyone can use there phones at the same time..I use my phone(plugged in as it drains the battery pretty quick on hotspot) as a Hotspot when I use my Ipad
5-And last but most important..A cell carrier that does not discriminate against hotspot usage..Verizon prepaid has no cap I am aware of for hotspot use and I have used alot..A Mifi has it's own data allowance but I prefer not to use my Mifi and just use the hotspot feature on my phone..