Well, 20K will become the starting point for raises and all, so it is not just a flat 20K. It is more. Besides, all the points and miles can also lead to free hotel nights for vacations and such.

If you have cover for childcare and have a little flexibility on travel (e.g., not travel when an exam is coming up, or a concert, or birthday), then go for it. If opportunities will not come too often in your region, I think you should give it your best attention.