Will Any Generator Do?

I don't see a reason why it wouldn't and since you said you would use it while boondocking (implying nobody else around) noise shouldn't be a factor of concern. Even the so called quiet gennies make quite a racket when having to supply any real power, just use a longer heavy duty extension cord with muffler facing opposite direction to help alleviate some of the noise and it will power virtually whatever your 5er has onboard. Generator probably needs some exercising anyway. Of course most public campgrounds have rules for generator use that all must adhere to regardless of brand.