On trips, at the side of the road or in a parking lot, I have replaced a couple of faucets, an Allison computer, several fuel filters, a broken idler pulley bolt, a furnace, reattached a headlight, rewired a trailer plug, replaced a shower dome, replaced batteries, replaced battery cable clamps, and done numerous oil changes.
Most technical job at home was replacing a seized water pump on a Cat.  Every fitting had to be at an exact angle and the sequence of steps had to followed, or something would not fit.  Took about three hours.
Most complicated job was replacing a black water tank that was melted by an exhaust with a broken mount.  It probably took 20 hours of internet research to find the best replacement, five hours to remove the old remains, and ten hours to install the new one.  An absolutely dirty, complex, confusing, discouraging, painful, dirt-in-the-eyes, sore back job.
ANY job done with the comforts of home, shop and full array of tools is a blessing.  Leaving your coach in the interstate emergency lane for four hours while you drive the towd to get a part is not fun at all.
Matt B