Congratulations on passing your General Exam. I've been a ham for many years but still remember getting my General License (1960) and how exciting that was. Ham Radio has provided me much pleasure since then, especially after retiring in 2012 and being able to devote many more hours to the hobby.
My wife and I bought our first RV in September, a 16' camper trailer (Cherokee Wolf Pup 16fq). Only had it camping one time in FDR State Park near Warm Springs. We had a great time with my brother, wife and one other couple even though we found a few more things we should have taken!
I am also looking forward to setting up a ham station to operate either in or out of our trailer. I have a rig (IC 7000) that I use when taking trips in the car. It's been a good and easy to use small radio that allows the face to be separated from the body so it takes much less room between the front seats of our SUV. I also use a "Tarheel Junior" screwdriver type antenna that has always worked well. An automatic "turbo tuner" provides much convenience in that it adjusts the coil in the Tarheel to tune it to whatever band and frequency you're operating.
I have a couple of portable (not mobile) antennas, a small vertical by Alpha Antennas and a "BuddiStick" by Buddipole. Both are very easy to setup and seem to work well.
When mobile, I operate the 7000 of the car battery with a well fused power line to the radio in the back of the SUV. Since most of the campgrounds have 30 amp, 120 vac service, I'll probably use that with a small 30 AMP MFJ switching power supply. When "boondocking", I have a 2000 watt Predator generator/inverter that I'll probably use. I say "probably" since I haven't either solution yet but don't see why either should not work.
I'm only generally familiar with the Yaesu 891 and it looks like a very nice radio for your purpose. I can say I've used Yaesus for many years and always liked them. I recently bot an FTDX-101D but haven't had a change to power it up yet. It's great as a home rig but much to large (for me anyway) to operate portable.
I read a review of the Pactenna mini (multiband model) which I assume you have. It looks ideal even when hiking because of it's size and weight. I'm sure it will work when you're camping also although my preference would be a portable antenna that would weigh in between 5 and 20 pounds. Not for hiking but very convenient for RVing. They can also be setup in a matter of a few minutes. There are many videos on both the Alpha Antennas and The Buddipoles (and BuddiSticks).
I wish you many enjoyable adventures with whatever equipment you go with and perhaps we can QSO between camp sites some day.