Based on the figures you have supplied and the cautionary notes about the MIRO's inaccuracy , I suspect your proposed outfit will be difficult to keep within the cars Gross Train weight limits and the towed weight limits.
You will be amazed at how the load you put into the caravan increases - even during a holiday. Its the little things that begin to add up and will take you over the limits.
Do bear in mind that exceeding the specified limits for the car will impact the validity of your car insurance, and degrade any safety margins the outfit might have.
100kg of pay load capacity will disappear very quickly.
The extra packet of biscuits, bottles of wine, magazines, maps and tourist literature, The new gloves, batteries for the torches, fluid for the toilet, a new full gas bottle, gifts for the grandkids, The extra pillow, hot water bottle, Bottle of hand soap and washing up liquid. etc etc etc....
I advise you either need to upsize the car or downsize the caravan.