Internship cancelled because of COVID-19, how to get the best outcome of the situation?

Hey,

I was interviewed for a trainee position for the summer of 2020 at a boutique investment bank, and during last week, they called me and told me that because of the current uncertainty of the COVID-19 they are not able to hire me at this point of time. They also asked if my exchange period during fall 2020 is cancelled (according to the current information it isn't), and encouraged me to contact them in case my exchange period is going get cancelled and told me that I could potentially do an internship during fall 2020 if my exchange period is cancelled. They genuinely seemed extremely interested in having me as an intern at their firm, and if I wouldn't be able to intern at their firm during fall 2020 (because of my exchange period), I would love to intern at the firm during spring 2021.

So I'm wondering what I should do at the moment to get the best possible outcome of this situation, for example, how much contact should I keep with the firm, should I keep contact with them through email or phone, etc.