I'd say given the situation, the sooner we do them, the better. Gameweek 26 for the final qualifying matches, and semis to start the following week? Gameweek 27 has 10 matches scheduled, they've not listed anything beyond that for now. Assuming each week's going to have a minimum of 10 games, I'd say just play semi leg 1, semi leg 2 and final in succession in weeks 27, 28 and 29, no point faffing around leaving "rest" weeks between rounds.
I'd also suggest the following in the event that the virus returns and they're unable to complete the season:
Cancelled before semi 1st leg is played: CL prizes go to 1st and 2nd in the qualifying comp
Cancelled before semi 2nd leg is played: CL prizes go to the 2 winners of the 1st leg of the semis (top prize to the SF winner with the highest score, 2nd prize to the other SF winner)
Cancelled before final is played: CL top prize goes to whichever finalist gets the highest score in their semi, 2nd prize to the other finalist.
Does that sound fair?