Would be fascinating if we ended up with basically Vichy France give or take some territory as the WAllies government due to more resources being put into Dragoon while the north becomes a Soviet aligned state.
I know 'immediate effects' are the main focus here but the Soviets probably couldn't afford to manage so much of Europe. The Warsaw Pact was just about manageable but All of Germany, Low Countries and much of if not all of France may be too much for a post-WW2 Soviet Union to handle, especially if there's any uprisings.
Note - I started writing this and went off on a slight tangent - sorry in advance.
If D-Day fails, then Operation Dragoon might not go ahead in it's OTL form - it was only approved a month before it happened OTL, and Churchill tried lobbying for it to be launched in Brittany less than two weeks before the operation went ahead, and before that, wanted to land in Trieste.
I would have thought that if D-Day had failed, then one of the intial responses would have been to send more troops into Italy (Probably American roops earmarked for D-day + 60 etc), and if Dragoon does go ahead, the troops, besides from perhaps the Free French Division, are drawn from elsewhere. Italy is not tank country, but even with German reinforcements, you probably see Allied forces on the Alpine foothills by the end of 1944.
Instead of Dragoon, I suspect you would see a D-Day 2.0 sometime in August/September 1944, which could be anywhere from Dunkirk to Brittany, or roughly around the site of OTL Dragoon. I suspect D-Day 2.0 would succeed, even if it involves strafing everything that moves within a 20 mile radius of landing beaches. The V1's and V2's would also be hitting Britain in full force by this point and Churchill would be looking weak domestically, so a Northern landing might win out.
Paris is probably liberated by Jan 1945, taking into account the winter weather, the possible lack of Mulberry harbours, and the butchery of the French resistance and anyone who the Germans don't like in Northern France following a failed landing.
All things considered, the Americans and the Soviets probably meet up on the Rhine in May/June 1945. I would be surprised if the Red Army would attempt to cross the Rhine if the Americans were through the Ardennes, given crossing the Rhine challenged even the Americans, and the Red Army had a general lack of amphibious capabilities and would have been fighting on a pretty long supply chain. Denmark and most of Germany are under Soviet occupation, as could possibly be some of the Netherlands, unless the British try to land in Frisia with some degree of German co-operation - see Operation Manna.
If for whatever reason, Operation D-Day 2.0 doesn't go ahead, fails, or turns into an invasion of Norway, Greece, or Trieste, then I would expect the OKW and the Generals in the east would have stripped the forces in the west of most of their armoured and veteran units to try and stop the Red Army on the Vistula.
Ignoring the effects that an Norway invasion (Not very much from OTL) Greek Invasion (Bulgaria in the western sphere?) or Trieste landing (Hard to tell) would have on the war, then by 1945, I cannot believe that the British or the Americans wouldn't attempt some kind of landing in Northern France. By this point, Churchill, Eisenhower, and Monty are probably not key players. At worst, you might see a landing in March or April 1945, possibly in the Med, possibly a breakout over the Alps (Rather bloody with even third rate German opposition) or D-Day 3.0 - And you thought June was choppy! This might be combined with virtually unopposed landings once the Germans have collapsed in Belgium, the Netherlands and maybe even North West Germany. If the Red Army does manage to cross the Rhine, they wouldn't get very far before they run into British or American forces.
France could, to be fair, go Communist after the war, particularly if a narrative develops that the Allies only swooped in at the last moment after the Soviets did all the work, De Gaulle is a British puppet etc...
With Denmark and Norway, it is entirely possible that the Swedes might have liberated/invaded in order to avoid being surrounded by the Soviets.
To conclude, you probably need a POD earlier than D-Day for a Soviet dominiated Europe.