Hello, we’ll go to Tianjin on oct 4 from Beijing. We realize it’s during National Holiday.

We plan to arrive at Beijing on Oct 3, spend a night there before going to TJ on oct 4 by G train, then plan to return to Beijing on Oct 8 or 9 and continue our sightseeing surround Beijing from there (which one is better, oct 8 or oct 9?)
Is it a good plan To avoid the crowds as we have to be at TiangJin on Oct 5 or do u have other suggestions? We have two elders and one toddler with us so need to plan accordingly, please give us tips about our trip as well. Thank you in advance!