My knowledge of the Whigs in US history is limited. I know they were supplanted by the formation of the Republican party, and much of its support came from former Whigs. Beyond that, I don't know exactly what a "progressive Whig" would be, and especially not if the term has meaning in British politics apart from whatever it means/meant in American history.
So the Whigs were a British political party (from which the American political party later took its name). In the 19th century, Whiggism was the name for a political and historical philosophy that believed that proggress was inevitable and that the enlightened (that is, upper-class liberal British people) had a duty to educate, tutor, and enlighten those unfortunate enough to be ignorant, whether ignorant Yorkshiremen, ignorant Boers, ignorant Zulus, or ignorant Indians and Chinese. Free trade and western institutions were clearly the best, so it was justified to impose them on other people at home and abroad. That's what I'm referring to.