WE HAVE AN OFFER!!

Last night our Iowa realtor called to say we have an offer on the house! YAY! It's very close to what our latest list price is, so we accepted it.
Here's the catch though... the buyers have 2 houses to sell (they have invited their parents to live with them, thus 2 families, 2 homes). Good news is that they have accepted an offer on 1 of the houses (contingent upon those buyers selling their house.... this could go on forever). Now they need to sell the 2nd home.
They have asked for possession on Oct. 1, which would be fine because we learned on Friday that we have to close on our new Texas home BY Oct. 14.
We have some definite prayer requests that we'll be able to afford the new house since we ended up substantially reducing our list price in Iowa. yikes.