if Germany won against mother Russia do you all think the allies would still have won?
Materially, they had the power to do so. The UK alone, if she fought to death would had likely been capable of defeating Germany with the resources of the Empire, let alone with the US. Would they actually do so? No, the blood cost is way too high.
No eastern front means that now UK/US are going to have to pay the bill of 10 million+ dead and multi years long horrible war, their populations will never agree to that, so they will make peace.
EDIT:
About new conquests, I think this colonazation of the USSR is going to be a total failure, a huge waste of money, lives and an awful quagmire. Honestly Hitler would had been best in getting limited more manageable territories with key resources, like the oil fields.