IMO 2020 will be held at Russia in July 8-18 (source), while IOI 2020 will be held at Singapore in July 19-26 (source). As the two places are far apart, it might be difficult and also tiring to attend both (if feasible).
As tmwilliamlin168 is so OP that he would qualify for both, and also some other people will fall into the dilemma of choosing between IMO2020 and IOI2020, so it might be interesting to see what would be your choice, if you get to qualify to both. Please vote here Link
More importantly, I would want to ask Singaporean CPers about if they got news about whether organizers would consider changing the date for IOI 2020, if not, please urge them to :) I would also want to ask this question to Russian dudes, but maybe its unlikely that they will see this post...