Thoughts are with you on this journey! You're halfway there with a willing donor!!
My son and I are also doing a paired donation in AZ if they can ever get his case advanced – I have been approved as a donor but don't match him (I'm an A and he's an O, and he's in his late 20s so they were looking for a closer age match). What we were told is this (do NOT take my word for it, just what I've asked/heard by my donor coordinator):
It is difficult (understandably) to predict timeframes but the paired donor blended average wait time is something like 90 days (this is what NKR publishes), but can range from 1-12 months or longer. It all depends on blood type of the recipient (O waits longer because there's so much demand that they suffer from being the most common type in need, but also the type who can give to anyone) and sensitivities of the recipient (difficult matches due to antibodies), etc. For my son (type O, not at all sensitized) we've had estimates from 2 months to up to 6 months to find a paired match. If the recipient is Type A and non-sensitized, I understand that's the fastest cohort to transplant.
Mayo is part of the NKR network for live donation and are a very well respected NKR program, and I believe their multi-center helps them out further (not fully sure) vs. a single region/single center? I was told that they don't just use their centers – my kidney could go anywhere and his kidney could come from anywhere.
My son is now on dialysis too, so really understand and empathize with you in how it increases your sense of urgency and makes waiting much harder – every day you wait means more than it ever did before.