We drove to Como in August last year - Took a day trip to Milan, passing through Monza on the train, so a similar route might work for you?
We took the ferry from Newcastle - Not the cheapest choice, but saves the slog through Englandshire and deposits you in Ijmuiden around 09:00 the next morning.
Plenty of options from there - We elected to head straight to Stuttgart, which was around 400 miles, but good time can be made on the autobahn at an easy 110-120 mph cruise.
Porsche museum definitely worth a look (no velvet ropes there!), and so is the MB museum apparently. We stayed at a Park Inn by Radisson which had an excellent secure underground carpark.
From there you could head due south to Milan via Zurich (around 300 miles), or take a detour via Austria and catch a few of the passes over there (we stayed in Innsbruck which was excellent, and drove over the Timmelsjoch to Merano which is a lovely little spa town just over the Italian border).
From Merano you can either take the direct route to Milan (3 hrs), or take a detour via Stelvio (which is worth doing if you haven't before, but will be very busy at that time of the year!!)
(BTW, Italian driving is, erm, interesting - Tailgating and ambitious overtakes are order of the day - You do need your wits about you

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