WELCOME TO APUG!!
How many ml does your tank need to process 1 roll of 35mm?
Couldn’t you mix up your full C-41, get 500ml of working solution, put your 1 roll of 35mm in the tank, on the bottom, then put a blank 35mm reel on top of that and develop? Dont do two since two need more than that amount of working solution that you have.
I wouldn’t recommend doing 120 also since it needs more than 500ml of working solution for your tank.
Also, I believe you have misunderstood the reply that Rollei-Film gave on 12-02-10, Rollei-Film was talking only about the stabilizer being able to be used twice without agitation. He/she said:
"Another question has been the working solution of the stabilizer. The stabilizer can be used twice. (Without agitation!)"
Last, I dont believe pre-washed film can ruin whilst sitting in water so long as it is light tight, but I defer to others here...