I have a BA (but Ex-BMI) flight booked arriving into T1 but I need to connect to a T5 flight. Obviously will need to follow flight connections etc and hop on the bus. Could someone with recent experience let me know rough distances to walk, escalators etc and time taken for the transfer. Also, is there any further security to go through?

I will be travelling with someone 1 generation up who is, shall we say, not quite as nimble or quick off the mark as me.

thanking you all in advance.