Thanks to everyone—you guys are most helpful and appreciate the info.
Couple questions:
1. Regarding diesel generator… the separate tank idea sounds like a good option, curious if are there any disadvantages to having TOO large a tank? I’m wondering about added weight or storage over time. Same weight question with having too large a battery bank… or maybe when you’re talking a 20k+ vehicle anyway, the fuel and battery weight is inconsequential?
2. Regarding solar—I’m curious about how practical it ends up being if you’ve already got a large diesel gen for long off-shoring. Of course would save on generator fuel, but I’m especially wondering (usage-wise) if most campgrounds are shaded anyway and since I’ll have a roof cover while on shore power at my house… I guess the solar would charge some while driving on large trips? But do you have any lower MPG from aerodynamics?
So maybe the scenario where it makes sense is a long-term trip in western US desert areas (for several weeks without shore power?).
the fuel tank CAN be too big... even diesel fuel goes stale, so it needs to be used down periodically so it can be refilled with fresh fuel....
the generator can be used for long periods, but burning $15-$20 dollars worth of diesel everyday, with all the noise it creates is NOT my style of camping, and neither do I want you camping NEXT to me with your constantly, or "often" running generator.... most others will agree.
batteries.... its nearly impossible to have too many batteries, except for the weight of them.... LiFPO 4 batteries are about half the weight, and deliver twice the amps, and are 4-5 times more expensive than a conventional flooded battery.... so, for those that can afford it, there are options for weight reduction of the battery bank...
solar... its the most practical way to maintain batteries... because it takes NO effort from you to start a generator, plug in a cord, or turn on a switch.... you dont even need to be in the vicinity of the coach for MONTHS, and yet the batteries will be kept charged and equalized... NO noise whatsoever...
unless you have a fairly constant NEED to run a component that has a high power consumption, solar is the best choice.... any one who has installed solar panels, and an inverter, AND have a generator, we find the generator rarely if ever gets used any longer.... this leads to the reason that most manufactures have stopped installing generators as standard equipment.. because solar is what everyone seems to want, which if done right, makes the generator obsolete for RV'ers...
BUT, Again, you are talking about camping in campgrounds. shaded campgrounds... if your going to be camping in a campground, there is usually an option for shore power... so, there is no need for solar or a genset.... if you like campgrounds and choose a more primative type without shore power, the shade will be an issue for panels... but the battery bank should allow you to camp comfortably for a few days....just like in the past, long before solar or generators were ever a thing in RVs
Within the world of RV life, it matters little how much power a system (whichever type you choose) is able to produce and store, we ALWAYS need to remain mindful of, and limit our power use accordingly... because when one doesnt do this, it can ruin batteries quickly.. and while its ruining our batteries, we are without the power we thought would just magically be there with as many amps as we could ever wastefully use.....
solar is the future, as it works quietly in the background.. but if we, as the manager of the system, do not care to understand its limitations and how it all needs to work together to be a long life, dependable system, AND mind our power usage, it can be nothing more than an expensive failed experiment.... at least until we decide to actually manage OUR power CONSUMPTION, and learn to conserve, just like EVERY camper that has came before, and ALL that will come after....
also, what some people dont understand about solar is, depending on the solar output and the size of their currently installed onboard charger, its easily possible to recharge the battery bank from the panels quicker than from shore power or the generator....
solar is a very viable system, unless one feels that their RV should have as much capability and capacity as their 200amp house system has... because that much power just isnt possible from our little 50amp system, which really isnt even 50 amps, because the 50amps is SPLIT into 2 separate 20amp circuits for use in our RV (and boats)......... its not possible ONLY because we dont have enough room for that many panels and batteries..