Wow! I think it's time for you to buy a new camera, Rob. The Nikon D200 is a 10mp DX camera released about 19 years ago. I searched the internet for information on the maximum card capacity the D200 can handle, and it appears to be just 8 GB, according to the following article.
https://www.nikonimgsupport.com/na/NSG_article?articleNo=000051983&configured=1&lang=en_SG
My Nikon Z50 is 20mp and can handle SD cards to a maximum of 512GB. When I bought the camera over 4 years ago, I used a 256GB Sandisk Extreme Pro card which still has 97GB of capacity left after 4 years of use.
SD cards are continually coming down in price. The next SD card I'll buy, probably in a year's time, will be a 512GB card.
Ray, I know perfectly well the size of my D200 files.
1. I have no intention of printing again, and when I did print A3+ prints, the output from both the D200 and D700 was perfectly good. The very last thing I can imagine needing at 87 is another friggin’ camera! Even when I was in business and could buy anything photographic that I wanted, I never bought Leica because the system wasn’t best suited to my work, and Leicas were always a bit behind Nikon in those days - not much seems to have changed. So, gear junkie I am not, and never was.
2. For use on my website, the iPhone is also good enough as makes no difference; the only thing lacking with mine is a reasonably long lens - circa 105mm equivalent. As for the two Nikons: on the website as in print, their output looks the same. Actually, I prefer the look of my stuff to the over-sharp look of contemporary machines. I can make what I have look sharper if I want, but the thing is, I don’t want.
3. More cards isn’t a route I’d want to follow. I guess there isn’t a product, then, that does what I was wondering.
Oh well, it doesn’t really matter very much, anyway, but thanks for the response.
Ciao -