Interesting, and yes, I do have two cameras with me anyway, always one for spare so I guess I could just set it up for use and run two speeds, didn't think about that!
Hmm good idea, get it delivered to Sweden, however, now I got hooked on this project, underexpose and push, and I'm already excited about "how could I find similar light conditions here in town next weekend"... So maybe I just go on with this, bring whatever Foma I have left, a bunch of Rollei Retro 80s to shoot at 160 in the second camera, and my 5 Efke rolls, and then I do have 5 rolls of portra 400 and 5 portra 800 that I'm thinking about using (not all of them) for some nice color winter pictures (maybe I need to bring a third camera then... hehehe!).
The portra I'm even thinking about shooting up to 1600 and get pushed in dev in order to take some evening/indoor shots in color too...