MrPopp
"How long is a piece of string" is a common expression here in the UK
It's very difficult to give an answer without knowing the type of stalking you're expecting to do.
That said, and in general, if you are shooting in Southern England, in woodland, or where roe and/or muntjac are the quarry then I would think it unusual to be faced with taking a shot over 150m - not impossible mind, but unusual.
If you are stalking moorland, in Scotland, or after fallow on open ground, then you might add another 100m on top of that.
I am presuming here that you are coming to the UK on guided hunting, rather than hunting on your own ground? If so, typically a guide will be conservative about your ability to shoot at longer distances until they know your capabilities, and many guides would draw the line at the above distances regardless (again, IMHO). Most will also prevent you from shooting at moving deer - a British custom that sometimes baffles sporting tourists who are used to practicing this discipline.
So far as scopes, a 6x42 or 8x56 would be fine, as would a 2.5-10x50 or similar if you prefer a zoom. Your 1.1-4x24 wouldn't be infeasible for woodland stalking, so long as you are comfortable using it to put three shots into a 4 inch (10cm) group on a target at 100-150m. You might be found wanting using it on the Hill though.