What about just shifting Luftwaffe forces east? As is was they were only getting slaughtered for no effect against the Western Allies, it only makes sense to put them where they could effect events. Even late war, with only 10% of a decimated air force, the Germans were still able to operate effectively against the Russians. Why no concentrate Bodenblatt against the Soviets and strike with the intent to maim? It would be possible to inflict some serious casualties on the Russians at this point and who knows, made even slow them down a week or two. At this point all is lost and if we are discussing about how to affect the Soviets a bit, this would do it.
Transfer the LW east and launch constant strikes and maybe a Bodenblatt against advancing forces, which they still were able to OTL and often win despite being outnumber by 3:1 or more margins. Withdraw from the Balkans and Greece and set up a line in Austria and Hungary and attempt to bleed the Soviets as much as possible. If the forces used at the Bulge were instead available in the East and the forces in the Courland pocket were evacuated and used in Prussia, then things slow down in the East considerablly. Let the Volkssturm surrender in the west to force the Western allies to deal with loads of prisoners that are useless to your war effort. The war will still end in an allied victory, but with hopefully higher Soviet casualties and and later allied win, with less Soviet violence against civilians during the war.