No doubt there are heavier riders out there, or tandem rider pairs.

Perhaps this would be a case for a steel rim, but I don't know what sizes they are available in. 26" and 27"???

As mentioned, Sturmey Archer also used to make 40h 3 speed hubs (available on E-bay).

But, I suppose a wheel every few years isn't too bad. I occasionally will bend a wheel, so I've replaced and rebuilt a few over the years.