There is a huge, HUGE difference between suborbital and orbital. The V-2 weighed IIRC, 28 tonnes with a 1 tonne payload. Supposing that a two-stage equivalent might get to orbit, you'd be able to launch ~70kg into orbit with a second rocket on top of the V-2.For maximum German space wankage, you'd need a satellite up by 1948 (not impossible. V2 already did suborbital) and a man up by 1950.
Then you have worry about guidance, non-trivial, the V-2 guidance system was totally inadequate. Also staging, which I know vB thought about, but did they have any actual experience with?
Some sort of token, non-useful satellite in '48 is probably possible. A man in orbit by '50!?!?!? No way, no how.
Mercury, the lightest actual orbital capsule is 1.355tonnes and was produced with later (lighter) tech. Vostok was 3x the weight. The Nazis have no experience with orbital reentry. Or building a rocket that's 28x the size of a V-2.