Hey @Smirke agree with the above for the trip I would recommend a installed unit, the range on the portable is still limited even though it is a 5W. We have the one in the car but also carry a handheld 5w for 4WDing so we can guide cars through tougher areas but also if we leave the car or split up we can still communicate.
Ronny from 4WDing in WA has just posted a video about some tips for the UHF but has some comments around handheld and inbuilt, worth a look
(No affiliation but a good video)
Ronny from 4WDing in WA has just posted a video about some tips for the UHF but has some comments around handheld and inbuilt, worth a look