Mine also don't get much light this time of year. Doesn't seem to be a problem for them. Spring and summer, when they are growing, they like a lot of light and fertilizer.

I don't think I have seen it mentioned in this thread, but most Cyms do require a period of cool nights - a couple of months, night temps lower 50s, late summer / autumn - to initiate spikes. So, for that reason, as well as their light requirement, it's best, if at all possible, to grow them outdoors from just after last chance of frost until just before first chance of frost.

That's why I leave them out until the end of October. They do need that cold period to bloom. I have even had the medium freeze solid in the pot, and all they did was bloom better.