Do you have a link for the "Stay 2 Nights or More and Save Up to 25%" promotion?
Mine just showed up when I searched for 2 nights and it worked just now again when I searched again on their regular website (now that promo price for Dec. 24-26 is $119 but still a smokin' deal). When I googled the promotion, it gave me this site, which does explain all the terms of the promotion, so you can use this:
https://www.wyndhamhotels.com/en-uk/hotel-deals/winter-savingsHere are some details (bolding is mine):
1. The Wyndham Hotels & Resorts Winter Promotion 2019/2020 (the “Promotion”) is a discount of up to 25% off the Best Available Rate per room per night
at participating Wyndham Hotels & Resorts hotels in Europe, the Middle East, Eurasia and Africa. The Promotion is applicable for bookings made between 15 October 2019 and 29 February 2020 on stays between 01 November 2019 and 06 March 2020 at participating Wyndham Hotels & Resorts hotels. 2. To qualify for the discount of up to 25% off the Best Available Rate per room,
bookings must be for a minimum stay of 2 consecutive nights. There is no maximum length of stay.