So sorry about all the travel troubles. Have you had your vaccine? I think you would feel safest traveling after you get your vaccine but I am not aware that the vaccine is currently a requirement for entry into Portugal.
If you own property here, You can travel on your passports as tourists. It used to be possible to apply for residency here having only come as a tourist BUT I am unsure if that is still the case. You still must have all of the required documents from the USA with you. You can check at the SEF.pt site for now and see if there is information there about travel to Pt. with just your passport but also as a land owner. I know that you will be required to have a negative COVID test at the time of bonding the plane and it must still be valid when you arrive.
I will try to investigate the following questions and I suggest you do also. Whichever one gets the answer first has to buy the other a glass of vino. 😀
1. Can you enter with passport & negative Covid test as a landowner? 2. Can you apply for residency here with just your passport and all required papers (list is on US portuguese embassy site) 3. how long can you stay on just a passport entry, are they allowing the "extension" of tourist passport stay at this time.
This might be an option for you because of the situation in the USA and consulates being closed.