It's pretty hard to overwater hops - in the field they need up to 60 litres per week at the height of the growing season.
And they're temperate plants, they don't like temperatures much over 30°C, certainly temperatures up to 40°C will make them unhappy - it was really noticeable here how all the grass died in the hot spell, or at least the grass that wasn't in shade - it was a combination of the extreme heat making the grass less able to cope with direct sun.
And in pots the roots are that much more exposed to high air temperatures, so they will be a lot more stressed than if they were in the ground.
If it's any consolation, commercial farmers will also be suffering reduced yields, at least the ones without irrigation.
Just as a general suggestion though, you're probably better off on a UK forum for this kind of "gardening" stuff, as it tends to be rather more local than the brewing side of things, eg :
https://www.thehomebrewforum.co.uk/threads/hop-plants-rhizomes-growing-report.69518/page-46