Somehow I doubt Roosevelt living would mean Soviet dominance over Western Europe.
http://www.answers.com/topic/yalta-conference (Looking at the Oxford Companion to US Military History and the Gale Encyclopedia of Russian History entries.)
If Stalin broke his promises - promises that if kept would make his requests/demands/suggestions more reasonable - like he did in OTL, why would Roosevelt trust him further (either as in continuing to trust him or granting him more confidence)?
I'm not saying this was FDR's finest hour, but it wasn't a sell out (at least not by intentions - and blaming FDR for Stalin being dishonest gets into the second half of this point), and it would have been difficult to come up with an agreement that doesn't lead to at least some Soviet presence in Eastern Europe without another conflict. Another
big conflict.
So taking one quote in 1942 as proof of what Roosevelt would do if he was alive in 1947 seems very unfair.