Yes and no. Things change, I think the Empire had to evolve to survive, in many ways it did, look at the emergence of the Dominions, yet in too many ways it did not and thus it tore itself asunder. One root problem was trade, the British needed free trade and lower cost imports, exports to the Empire were not significant and once the notion of a trade bloc is seen the domestic industry is far too disadvantaged to thrive. And I agree, the closing of the global trade place and shift to fencing in your bloc was likely more hurtful than we can fathom to the Empire. Add to this the snobbery of the English who in this era not simply feel culturally superior but also racially so, a sentiment that not simply alienated African or Indian but set wedges with the "white" Dominions too. Even if we can keep the Empire sidelined in the Great War one must consider Irish Home Rule. In certain ways that was the test and the first string pulled to unravel the Empire.
Without going back further, I think the best starting place is the Great War, have it be without the British openly in it and give the Irish a way to regain their independence yet stay at the table. From that you wash away the crippling debt, the loss of invincibility, a Europe far removed from the eternal brink of war, familiar trade patterns surviving, the Empire left as the strongest European power. You still have India who will one day reassert her independence but even without it, the Empire had relevance if the Dominions become part of a Sterling dominated trade bloc, not a closed one but one linked by improving shipping, communications and continued cultural influence from Britain. A multi-polar world with the British Empire, Russia, USA, German Empire and Japan should give the Empire a place to fit in a world both more settled and still competitive. At that point British industry can better renew itself to compete globally like the USA and secondarily the Germans. We can at best get a world of peers, if the proud London barons can accept that fate then London remains one of the centers of the world and they hold far more power than they do today.