Sucessful invasion of the SU was far from impossible. Once it started (22nd June 1941) most mistakes were already made, which made it almost impossible to win. Worst part was actually a poor logistic planning by Halder for Barbarossa (apart from the additional mistakes I mentioned).
They had river barges being towed by tugs without enough men to man them which would sink in anything rougher than sea state 2. I'm not sure that counts as transport.
Yes, definitly.
Considering the progress until November 1941, the campaign for SU was actually almost won.
Even if it was not a completely 100% effective blockade, it should be enough to make keeping the troops supplied difficult and the cost of delivering what little did get through should be high.
I am not 100% sure if replacement equipment can be sunk and lost, but what can be done is this. The supply convoys exist and can be attacked. Hitting them will reduce their efficiency which in turn will lower the supply capacity. This will slow down the rate at which replacements are received.
Check what the biggest country on Earth is now. And USSR was even bigger. You have real kilometers to go through, not the impression given to you by the pole stretch. About 1000 to Moscow and 2500 to Perm.
You're right, instead of being "impossibly huge", it's merely "positively enormous".
Always depends on how you define "biggest". If you define it by length of border or amount of people, then it is not Russia...
I doubt a SU surrender would have required jetting all the way to Perm...
Okay, so even taking the assertion that the German army was the strongest in the world at face value, the German army isn't the problem with pulling off Sealion, as all the Wehrmacht could hope to do was stare angrily across the Channel. Sealion depended on the utter annihilation of the RAF and the Home Fleet deciding to just call it quits, and on top of that, for Mother Nature to play really nice. The first point was impossible because the RAF was growing throughout the entirety of the Battle of Britain, while the Luftwaffe dwindled (and no, Germany never had the RAF on the ropes as the RAF still had completely fresh forces in Scotland they could have rotated in if they were actually needed, and you must think the British are a truly weak-willed people if you think a few months of strategic bombing from tactical bombers was going to break them when years of far more intense bombing failed to break the Germans). The second was also not likely to happen, since defending Britain proper was literally the entire job of the Home Fleet and the Kriegsmarine was a joke with no hope of defeating them in the field. And the third was necessary because Germany did not have the kinds of merchant shipping needed to actually land and supply an amphibious invasion and would have had to rely on river barges that would have suffered horrible attrition in the rough waters of the English Channel.
1.) A lot is that, yes, but you're still looking at a huge amount of land in the east in the same ballpark as trying to bite off everything in the continental USA west of New Mexico and Colorado (assuming their western border stretched all the way to the Canadian border).
