Well, here's my interpreation of a Entente vicotry in tl191, with trying to stay as much to OTL as possible. I think the Eastern hempsphere would be pretty much OTL. But in Wmeirca, i agree that the only way entene victory over all is either the CSA and Canada beat the US ealry on in the War, and then concentrate on europe, but this is unlikely considering the situation of the US Armed Forces and economy.
The only other way i can see it without a decisive first stike, is that the Entnete make a breakthrough in europe early on, Ie, Gallipoli Campaign is a succes (Gallipoli still happens in TL 191 doesnt it.), or at latest, the British and French Force a Breakout at the Somme, and the Brusilov offensive in the east is a succes, (I honestly don't know if these happen in Tl 191, it's been a logn time since i read them, but i remember Marne, Mons, Ypre and Verdun Being Menioned)
Anyway, i see Canada annexing Alaska, I doubt they would let the reds have it, and i think that in the event of the reds winning the civil war, there would be alot of White russian emigres, anyway, they will probably annex Oregan and Washington, and incorperate it as a province (I place bets on it being called Cascadia) and Occupy Nothern california, aswell as aneexing most of Idaho and Montana. Plus they would probably annex Maine, Vermont and New Hampshire (i think they would eventualy incorperate it into one province, imagine the uproar if they name it British North America
) and put Boston within artillery range. Then maybe most of the land around the Great Lakes, endangering Chicago. and taking buffer territories aound Niagra and the St lawrence river.
CS would annex Maryland, West Virginia, Kansas, Arkansas, Kentucky, New Mexico, sotuhern illonois, and Southern California, Once and for all cutting off the US form the Pacific (wankish, but wouldnt it be in thier intrest.) Hawai stays british, (I imagine it was more or less a protectorate, with the Hawainn Royal Family still ruling, but with shitloads of british advisors, much like the Indian Princely states) or perhaps the british think that it would be more in thier intrest to hand it over to Canada. Mexico probaly doesnt feel the need to annex anything, as it is now totaly cut of form the US, but now more a CS puppet than ever, Cs now Deffantly gets Porto Rico, plus i think they would occupy most of the industrial US, much like the Rhur in OTL.
Argentina (they were on the entente side were they not) annexes some of Sotuhern Brazil, Southern Chile and a little bit of Paraquay.
So Now you have a US that is Totaly Crushed, and i realy don't think that in the event of a Second war, they will do anything, most US politions would probably be contempt to go for the Satus Quo, or though i imagine there would be a huge degree of civil unrest, particualy in the industiral workign class areas, where you might have communists fighting some sort of equivilant to OTL Nazis.
BTW, whats other oppinions on the possibility of a Second War, i think japan will emerge as the Main problem though. for the Allies though, But i imagine this it will emerge as a Britwank more than anythign else.
(I meant to psot a map, but i wouldnt let me, and sorry for any mistakes, innacuacies and crap ideas)