Completely correct - the groundspeed is completely unrelated to the actual speed that the aircraft 'thinks' it's flying at - ie: how fast the air is flowing past it. I've regularly been on flights where the groundspeed was between 1100-1200km/h but the airspeed will always be within the usual range for that type of aircraft. In fact, last week I was on a flight JFK
on a 744 and made the crossing in about 5hrs 15min, makes the journey very easy!
So rest assured that there's no risk of the aircraft 'breaking up' just because it has a very high groundspeed - in fact the crew probably wouldn't even notice unless they happened to glance at the groundspeed indicator - all the flight measurements are based on airspeed.