My state doesn't have a foreclosure auction calendar that shows ALL of the upcoming foreclosure auctions, that also reflects postponements (important) and cancellations.

Ask the seller if his property is in foreclosure and if he/she says no, let him know there are sites stating it is and then if still not satisfied, you can confirm if its in foreclosure or not by getting a prelim for a nominal fee.if it is and its just the notice of default, there is time but if its the notice of sale, there is little time but still, if there is a deal to be had, the seller can request a postponement showing that they are under contract and anticipate a close shortly.

I locked in a rate in Aug, closing got postponed a month and now I am facing a $2,000 rate lock extension fee to keep a higher rate than what is offered now.  

Or do I want to postpone it to the following year? 

You should inform the title company that you'll be assigning the deal to an end buyer, so they postpone the municipal/lien search but proceed with the title search to ensure there are no issues with the title.

I've seen a lot of deals which look great when the numbers are run only to find out that there is a lot of "postponed" maintenance.

What is happening now is that showing traffic is down about 45%, people are doing virtual showings, listings are being postponed until after CV and the cashual buyers have stopped browsing.

Furthermore, how long can a subject-to buyer typically postpone full payment.

The auction sale was postponed INDEFINITELY.

I’ll postpone the meeting until we have some confirmations.