Look at your own online stats and you will know when is most convenient for everyone. I'm happy to play the larger stakes, but I have a strong preference for a full or near-full table. How we get there I am not sure. Getting HU or 3-way just becomes very volatile. Most any table of six or more players, I will sit.
When I was playing in China, all the cardrooms in a particular city compete for the same pool of players. If everyone show up at Room A, then Room C might not have a game that night. So often certain rooms will text everybody: 'First three players to show get 10 Big Blinds to play.' Of course if you show up at an underground poker room in China and take free money, you're gonna sit for a couple hours at least, as a courtesy to get the game going. Otherwise you might piss somebody off ... lol. I don't know what the online equivalent would be.
Previously I suggested you recruit a 'pro' like plo8monster who is prepared to sit all day, all stakes, at your cash (ring) tables. You might think about that again and start casting around for someone. I know at one point Satoshi Poker had 3 pros who were staked by admin. Then, two of them purposefully donked their chips to friends so it didn't quite work out. But there are ways to make it work I think ...