My Iberia flight was cancelled, what are my options?

I am planning to travel from Portugal to Norway in June, and I have booked the return flight from Bergen, Norway to Lisbon, Portugal through Iberia. The booking actually consists of two flights, one from Bergen to Madrid, and then from Madrid to Lisbon.

I have noticed on Iberia's website that the Bergen-Madrid flight has been cancelled and I don't know what I should do. I've checked this "air passenger's rights" site and it claims the following:

The airline must offer you, on a one off basis, a choice between:

the reimbursement of your ticket and, if you have a connecting flight, a return flight to the airport of departure at the earliest opportunity

re-routing to your final destination at the earliest opportunity or,

re-routing at a later date at your convenience under comparable transport conditions, subject to the availability of seats.

But I am not sure that I am interpreting it correctly. It seems to me that the airline must offer me the above choices, and that choice number 2 would be an equivalent flight from Bergen to Lisbon approximately on the same date.

Am I interpreting this correctly ?

I have filed a complaint on Iberia's website, but their response time is 21 working days, so it will probably take a while before I have a concrete answer from them.

In the meantime I don't know if I should assume that my trip will still happen and continue planning it, or if I should wait until I have a confirmation from Iberia that I will indeed be able to travel. I still need to book a car and a hotel, and the more I wait, the more expensive they will get.

Any advice on how to proceed?