i think if you really want them to have a good time, u may check out the places, explain to them and let them decide.
Guided tours are usually quite tiring, you change hotels every night, go to appointed stores for compulsory demo (everyday).
It is true that it is definitely cheaper (before the tipping), you cover more places, tried more food.
But is it really more pleasant for the elderly?
It will definitely be physically tiring.
Btw , it is winter time and it will only get colder for the next 2-3 months.
I suggest doing some homework before deciding where to go, or which package to choose.
btw, it seems like the southern provinces , e.g. shanghai, zhejiang may not have centralised indoor heating.
So if u really go for free and easy (quite unlikely since u would need a lot of preparation/ reading up before hand), u need to take note.