Nobody knows how long the delay is. The normal processing time for an amended return is 16 weeks. But the IRS processing centers were closed for several months because of the Covid-19 pandemic, and they did not process any mailed tax returns, including amended returns. Your amended return is probably sitting in one of the large trailers outside the IRS processing centers filled with millions of pieces of unopened mail. They just recently started to reopen the processing centers and process mailed tax returns, but they have reduced staff and a huge backlog, so it will be a long time before your amended return is processed, or even show a status on the IRS web site.
