Welcome to the forum from Pa. If the bike has been maintained properly it could go many more miles. If your not handy, take it to a dealer to be checked out. You may have a good bike with a lot more miles left in it..
I got 186,000 plus on my 93 and it's still looks and sounds like new. Change the fluids Oil, engine and differential, coolant and have the brakes and clutch flushed and bled and go for a ride. Should be good for another 100,000 at least if it's been taken care of.
I can tell you it all comes down to how you look after it. In this case how well your father looked after it. An Gooldwing owners tend to look after them very well. Last year there was a 1986 1200 wing here for sale with 595000 km on it and it looked great. Eric
what you need to do is read the Goldwing 20 Anniverasry book and see what kind of engineering and torture testing they put these machines through. While nothing lasts forever, a Wing just might come close.