In short, Yes. It's important to remember that Hitler's racial views were not binary in the sense that one may think. In order to answer this question, let's forst go into context about Hitler's racial views in Europe

For Nazi Germany, there were certainly various groups of people that fit somehwere in the middle between Aryan and Subhuman. Notably, Hitler liked Northern Europeans such as the British and French and believed them to be "harder working". Where things get tricky is to what extent Hitler's perception of connection between Northern Europe and Germany is based in reality.

For Instance, the British TECHNICALLY have Germnaic Roots, with Angles and Saxons being Germanic tribes during the antiquity Era, which may have meant that Hitler saw them as one in the same from the time of the "Aryan invasion" in India. The same goes for what Hitler perceived to be the ethnically French population, as the Western Frankish Kingdom certainly has its Historical ties with many regions of modern day Germnay. For more information on Hitler's Aryan theses and the historical myths that based Nazi ideology, I would encourage you to check out the Ahnenerbe and sources on it.

That being said, Hitler considered "ethnically Slavic" people to be subhuman. Consequently, when capturing populations of Russia and Eastern Europe, their treatment was abhorrent, with little to no regard being given for wellbeing.

The "Northern Europeans" as Hitler perceived, such as the British and the French, were subsequently better treated as a result of Nazi racial views. Hitler's invasion of France was strategic in many ways, but also politically motivated to avenge the treaty of Versailles. Similarly, Hitler initially didn't want to invade Britain, and like you mentioned, Chamberlain was not particularly hostile to the Third Reich. Hitler's ideological views had nothing against the British or French, and so there was no reason to try to elminate them.

In essence, Germany's final solution and expansionist ideas were always focused east, whereas the west was nothing more than a political and military rivalry between (relative) equal. From a purely logistical standpoint, Occupation in France was in many ways similar to traditional occupation from an invading force, with the the GLARING exception of course being the ethnic cleansing of French Jewish populations.

With Russian POW, Hitler viewed them as all as Subhuman, so occupation of east territory meant that the "Subhuman populations were to be removed. As such the treatment of Russian civilians and POW were astonishing.

This goes without saying, but as the war situation worsened for Germany, tretament of POW across the board worsened as food and other essential materiel became increasingly scarce.

TL:DR. Nazis had nothing ideologically against the British and French and treated them better, whereas Soviet and other perceived Subhumans were specifically treated terribly.