Q, as I am sure you are aware, in 1715 there was no such thing as standardised spelling anywhere in the English-speaking world, and consequently no "wrong" way to spell a word (or "right" way either).

Men of letters were perfectly happy spelling the same word in different ways, sometimes even in the same sentence.

Nowadays, for better or for worse, we do have standardised spelling, and the standardised spelling for Scotch is whisky, for both single-malt and blended.

I do agree with you however about avoiding blended whisky ...