A quick look at the schedules of both teams and it looks like there are only a few options if this game does, indeed, get replayed.
Monday, April 22 - Cubs are in between home series and LA finishes a home series the day before and start a series in WDC on Tuesday, April 23. I don't think they'd reschedule this quickly.
Monday, June 3 - Cubs are in between home series and LA finishes a home series the day before and start a series in Pittsburgh on Tuesday, June 4.
Thursday, September 12 - both teams finish their series against each other in LA on the previous day and have this day off. Would take away HFA (obviously) for the Cubs.