When will the REMOTE1 be available again?
As of now (last update: January 31 2022), the REMOTE1 is sold out and discontinued. There will be a successor, which can be used for controlling both the AMP X and the AMP1, but it will not be released before 2025. Unfortunately, we cannot deliver this product until further notice.
Your best chance to track down a REMOTE1 is to look around on the used market (on places such as eBay, Reverb, etc.) to see if any are available.
Info
Did you know that you can implement the full range of functions of the REMOTE1 with the help of the MIDI1 interface adapter also via MIDI? You will find more information on this topic here: What are the switching options for the AMP1?