Would appreciate some guidance for a one way ticket.

I am traveling from MSP to ATH and need to be in ATH on June 1. In looking at Google Flights, Icelandia has the cheapest fares, but the cheapest flights have 2 stops, which makes it a 17 hour trip. I am trying to find a different gateway city to Europe. It appears the best option is to buy a RT ticket to another city, then purchase a one way to Athens.

Would love to spend miles, if possible, but not mandatory. I have miles on AA and Chase UR. Would appreciate guidance from one of you routing experts.

TIA