Arnold from Denver mentioned something in a recent post that I was unaware of. I think it deserves to be highlighted because it could potentially benefit a lot of folks who have United frequent-flyer miles to use. As far as I can tell, this isn't a time-limited special offer, though the policy could change at any time. It's called the "excursionist perk".
https://www.united.com/ual/en/us/fly/mileageplus/awards/travel/types.html
I haven't used this myself, but this is my understanding of how it works from reading that website: If a traveler takes a multi-city trip to a different part of the world (such as Europe) paid for with frequent-flyer miles, the traveler can include a middle segment within the destination area at the cost of no extra mileage. The traveler does have to pay taxes and fees.
I bet a lot of frustrated folks will do extended trips next year; some itineraries would benefit from having an intra-European flight segment in the middle. Taking advantage of the excursionist perk could be cheaper than using a budget airline for the intra-European flight.
I am not clear on whether the free (except for taxes) flight has to be a non-stop; the United website doesn't seem to indicate such a limitation. If it can be a trip that requires a connection--and would require a connection on a budget airline as well--this could be a big money-saver. Two-flight budget-airline trips can get quite costly with checked-baggage fees.
Thanks to Arnold for his heads-up on this.