goal is to hold the line into winter and use energy as a weapon against Europe in the hopes NATO will lose heart due to their internal politics. That's all. Seems like ok common sense to me.
NATO countries have some pretty bad economics and politics right now. UK is in a deep recession and political scandal. Italy is about to elect an ex-fascist. Macron is weakened. Germany is in energy crisis mode. The pro-putin Rs in America are likely about to paralyze the US government. Everyone is looking at stock markets down 20%, much higher borrowing costs and probably recession. Pretty easy to visualize NATO countries saying 'we come first' and reduce aid to UKR.
It could go against putin if mass waves of Rs manage to surrender to Zelenskyy. Yeah that would be embarrassing. But not likely.