Usually both the live view & the control signal will go pretty close to each other if affected by severe interference or going out of LOS... loosing the control signal will trigger failsafe RTH already after 2sec after it's lost.
I would try 2...
I think it's that simple in practise...
DJI photo drones have always been limited in tilt+speed by the firmware. The drone will be able to make headway at max speed (here meaning ground speed) all the way up to when the (fw limited) tilt angle...
This isn't a mystery at all...
A Mavic 3 Pro have a max speed of 21m/s according to spec... a direct headwind of 21m/s will then stop it, & faster winds will push it backwards. DJI states 12m/s as "Max wind speed resistance" ?
A Mini 4 Pro...
If nothing regarding firmware bugs prevent your drone to be used... I would say that for as long as you want. The major obstacle that in the end will render your drone setup useless is the batteries, once those no longer can be sourced you're...