I did a little research on Baltic sea travel/trade, Finland and the German merchant fleet available. When WW2 started Germany had 400 merchant ships, of which 80% were in foreign ports on 1 Sep 1939. That leaves less than 75 (accounting for losses in Norway) by Spring of 1941 for building Wehrmacht combat power in Finland (which is crazy, since 90% of those ships were involved in shipping coal and iron ore to German steel factories). Only Helsinki had cranes capable of offloading tanks as well as the corresponding piers, railyard, etc. The port freezes sporadically in winter (until 1 April) and requires an icebreaker, of which Finland had 1 only. The ice and winter conditions preclude any buildup until spring, which includes any air transport due to terrible conditions, limited warehouse capacity and limited airfield capacity (which was in use in Crete/Med anyway). So basically you have a single port with limited monthly tonnage capacity, limited rail capacity and close very proximity to the Soviets. The port is mathematically incapable of supporting the force structure suggested in the OP and it is also mathematically impossible to simultaneously deploy and build a logistical base from a small port in a very short period (less than 90 days). This by itself makes the scenario a complete pipe dream... It is logistically impossible. A single Pz Corps with a single Luftwaffe fighter wing would be quite a stretch IMHO.