It's a question not exactly IB-related, but I guess this forum knows more about Madrid airport than most.

A simple matter of transferring from T1 (TAP from LIS arriving 11:35) to T2 (TG to BKK 13:00). Baggage will be checked through, so we are talking airside transfers and not a great deal of time.

How easy is this for an older, slower passenger who I know () will refuse assistance.

Aena's website isn't a model of clarity on this subject.