Should I wait until spring to repot?

[Bulbofett]

I have this oncidium I bought a few weeks ago, and I feel bad for the poor thing sitting in this gross sphagnum. I'd like to repot it into some bark like my other oncidium, but don't want to stress it out too much since its winter.

It has 2 new growths as you can see in the picture (other growth is just peeking above the pot there). Would repotting now be a good or bad idea?

Also, I think one of my outdoor plants brought some little ant friends with it, and they've taken up residence on this guy. They only crawl on the new growth. Should I exterminate them, or are they harmless?

This now makes 2 oncidiums I have pity purchased and I have no idea what blooms I'm going to get. Kind of exciting!