PHEVs of all makes are something of compromise, but they can make a lot of sense for some people. There Are generally two approaches to the way a PHEV is implemented, and I'm not certain how the Outlander is configured. Some only use electric motors to drive the wheels, so the inclusion of the IC engine is simply to act as a generator. Others have the option of electric drive or IC drive, And a there is another simply a hybrid approach where the electric motor is just a supplement to the IC engine to boost performance as in formula 1.
With such a variety of uses I think we could expect to hear about a lot of electric motor failures, but I can't recall reading about many problems with motors, more often it's the other equipment that has been at fault.
In general the emerging history and evidence is that the motive power electric motors are proving to be more reliable than even the manufacturer's were predicting, and the same applies to the batteries.
The foreseeable problem with the PHEV approach and caravanning, is that when thee vehicles run out of battery charge, they have to rely entirely on their IC engine to provide the power. Some makes have earned a notorious reputation for poor fuel economy. I hope the Outlander is efficient enough for you.
Please keep us informed.