Following up...many, many hours on hold with Chase and SQ later.

We were finally told that we could "cancel" (no-show) and get a travel credit for use on SQ (or as long as one leg was on SQ metal, other codeshare partners--we'll see about that) for travel on or before one year from the date the ticket was initially issued. We didn't have to pay upfront the $200/pp fee.

We realistically can't use the credit for travel until Nov Dec, so a couple of months wait until rebooking is worth it for us, both in terms of likely sale prices and determining what this coronavirus panic will do globally.