Try 5, maybe 10 years. Then figure out a way for them to mass produce the weapons. Then figure out a way for them to do it while being engaged on three fronts without strangling their supply to deployed forces.
In other words, figure out a way to make give them the resources of the United States AND the USSR.
Otherwise, this is just like all the other, Nazi wonder weapon WI, borderline ASB. Germany came up with lots of innovations because they were getting their asses kicked & they were willing to try anything to hold the wolf from the door, even for a day. The problem was, they WERE getting ther asses kicked which meant they lacked the resources to make practical use of whatever they managed to come up with.
Even if they HAD managed to deploy these weapons, the allies, given their overwhelming industrial potential would have quite quickly found a way to call, and then raise.
Best case (if you want to call it that), if the Nazi's had managed to get all the super weapons in place? Germany gets nuked, and the Red Army meets the Western Allies on the French border.