They might partial default, but I don't think it will be a full one. They will in all likelihood go down to the wire and then not do it. They might be willing to default partially though as a way of testing the market and dumping some of their debt
Both parties will be have their full stupidity on display, there the printer will run in the end. No doubt that this type of drama-filled idiocy will provide even more context to those countries considering (and beginning to accelerate) de-dollarization.