A little preparation goes a long way.
Check documents, payments, hotels and transfers separately, then plan Shanghai, Jiangnan or Beijing around usable travel days.
Start with actual travel documents
Consult the National Immigration Administration guide for the Mainland Travel Permit for Taiwan Residents. Check the actual document and its validity. Family members with different documents need separate checks rather than assuming one process covers everyone.

Prepare phone and payment access
Before departure, check SMS access in mainland China and complete requested payment-app verification. Cards issued in Taiwan remain subject to the app and issuer’s conditions; linking does not guarantee every transaction. Keep an independent backup.
With parents, inspect a real day
Start with “four people, six days, less walking and comfortable rooms,” then inspect hotel changes, transfers and evening outings. The five-stop, six-day outline is busy; removing a stop can make more difference than simply starting later.
Quotes and communication
Ask for an explicit currency, per-person or family total, room count and flight inclusions. Traditional Chinese communication is available. Agree on a usable on-trip contact method before departure rather than relying on a last-minute app change.