As noted in this article from Encylopedia Britannica 1911, the great dividing issue between Whigs and Tories through most of the 18th century was on the role of the crown in the executive of the government. The Tory position was that the King was his own "Prime Minister", a hands-on chief executive in the current American model. The Whig position was one of Parliamentary supremacy, with the "majority leader" in the Commons acting as chief executive of the government, with the King a figurehead, after the current British and Canadian model:
On the whole, during the last years of the 17th and the first years of the 18th century the Whigs may be regarded as the party of the great landowners, and of the merchants and tradesmen, the Tories as the party of the smaller landowners and the country clergy.
... the real conflict was between the corrupt influence of the crown and the influence of a clique of great landowners resting on their possession of electoral power through the rotten boroughs
With the madness of King George III, and changed priorities following the French Revolution, the dividing issues between the parties became Parliamentary reform (Tories initially pro, then later con) and continuance (or not) of the war(s) against The French Republic and Empire. Although the old party names continued in use, many important members of both had re-aligned.
In the years following Waterloo, and triggered by Wellington's refusal in 1830 to support any Parliamentary Reform, the Tory and Whig parties splintered to be replaced by the new Conservative Party and Liberal Party.
Many senior members of the Conservative party continued to think of themselves as Tories, and to refer to themselves as such, such that the appellation is still in common use today:
Shortly afterwards the name Tory gave place to that of Conservative (q.v.), though it was cherished by those Conservatives ..., and who disliked to be branded with a purely negative appellation, and it was also retained as a term of opprobrium by the Liberals for those whom they regarded as old-fashioned opponents of reform
In contrast, few if any senior members of the new Liberal party thought or referred to themselves as Whigs. The name rapidly fell out of fashion in Great Britain though it continues in popular use in Canada to refer to the Federal Liberal Party.
It [Whig] ceased to be a name accepted by any definite English political section.
Thus in answer to your question, by the time of Queen Victoria's ascension in 1837, both the Whig and Tory parties were defunct, replaced by the Conservative and Liberal parties. For the preceding several decades they had both been diverging from their defining ideologies as they diminished in importance on the political landscape.