Everything depends on what you want/expect from your trailer.
Having exhausted all iterations between a simple bedroll through various types and sizes of RV's, we've at this point decided that the fewer the complications the more we enjoy the trip, so have settled into a mode we call "hardsidedtent camping". That means we have a very small, simple trailer that provides shelter, heat, refrigeration/cooking facilities, onboard water, a porta-potty, and lights. All immediately and constantly available without having to "set up". We ask nothing more from it.
By keeping our needs to those minimum standards, we drycamp/boondock for up to a week in winter, longer in summer, on a single deep-cycle battery and a twenty pound cylinder of propane. The only electric demand is lights- even the heater has its own self-powered fan. Thus no necessity for genset or solar panels.
Since we're scheming about a bigtime/longterm trip around North America, our style will likely change in future...but it works really well for our Outdoor Recreation camping right now!
" Not every mind that wanders is lost. " With apologies to J.R.R. Tolkien