I think Polystralia might be a decent pick for an OCC. 2 extra trade routes is huge when you only have one city. I just played an OCC with Hutama, and the extra trade routes helped a ton. Early on, they allowed me to connect to stations for extra production (to get those wonders out pronto), while still getting some big science and energy from the extra international trade routes. Later, two extra international trade routes meant an extra ~20 science and energy per turn. For a good part of the mid game, the science generated by trade was about equal to the science generated by my one city.
In general, I think an OCC (or tall, in general) is very viable. I didn't play particularly well (and had a terrible starting position), but only noticed a bit of slowdown during the midgame (when going for the first outer-edge techs) compared to my "normal" plays so far. Prioritizing the extra science from academies virtue might be crucial, as that is the point my high population kicked science generation into higher gear.
Terrain maximization will be key when going OCC/tall. Avoid a coastal city unless you fear your trade partners may be overseas (non-protean world). Coasts get a quick early boost but then never improve again. More importantly, your coastal tiles will constantly be blocked by nearby krakens/sea dragons.
The techs that boost farms may be worth gunning for, escpecially if you get the farm boosting wonder, though the +production and +science ones are quite far out. Academies are key. Terrascapes aren't really worth it, unless we can somehow shoehorn that last Prosperity-tree virtue in there relatively quickly (probably at the expense of Industry). Otherwise trade routes, farms, academies (which also get +1 culture from tech) and the occasional mine are just better/cheaper.