The distance from Vladivostok to Hokkaido is about 415 nm - and this is not necessarily the distance to a landing beach, just the closest point. The waters between Vladivostok and Hokkaido, especially in winter, are pretty rough. The range from Vladivostok is at the very max for an IL-2, the Yak-9 can get there and have some loiter time. This means any air support for landings will be limited at best. The Russians have never done a major amphibious assault of the size that would be needed, and certainly not over this sort of distance. IMHO at best the Soviets would have to wait until spring of 1946, doing it over this distance with these numbers. Pulling this off with no experience for the Soviets would be quite a feat. The USA worked for a long time to get the equipment, the doctrine, and training to pull off these sorts of amphibious assaults.
Assuming the Soviets could get enough of the equipment - landing craft, transports, etc - and practiced a lot, they could give it a shot. Minimal air support, minimal naval gunfire (they had no major ships in the Pacific or anywhere for that matter) they Soviets will have a very bad time of it. Absent naval gunfire and proper air support any Japanese defenses that are dug in, and they will be, will be there waiting. By spring 1946, if things are still going on the Japanese on Hokkaido will expect the Russians to come and will do their best to make it expensive.
If the Soviets are willing to pay the price and they have some luck, yes they can take Hokkaido. Given the logistical issues in getting what they need for the navy, training troops and sailors in amphibious warfare, the water conditions in that area in the winter...doing it before spring 1946 would result in failure.
Assuming the Soviets could get enough of the equipment - landing craft, transports, etc - and practiced a lot, they could give it a shot. Minimal air support, minimal naval gunfire (they had no major ships in the Pacific or anywhere for that matter) they Soviets will have a very bad time of it. Absent naval gunfire and proper air support any Japanese defenses that are dug in, and they will be, will be there waiting. By spring 1946, if things are still going on the Japanese on Hokkaido will expect the Russians to come and will do their best to make it expensive.
If the Soviets are willing to pay the price and they have some luck, yes they can take Hokkaido. Given the logistical issues in getting what they need for the navy, training troops and sailors in amphibious warfare, the water conditions in that area in the winter...doing it before spring 1946 would result in failure.