It's actually worse than that in design terms. OR.343 required normal operation from a 1,300 yard runway at ISA + 30 degrees Celsius, and emergency operation from a 1,000 yard runway at the same temperature - or just 600 yards for the 450 nautical mile sortie. All with a target LCN of 20.
That would allow operation from Stanley in terms of length, but not necessarily in weight, though the shorter sortie presumably involved less fuel and therefore lighter weights. I've no idea how much lighter, or what the relationship is between weight and LCN.
Realistically, TSR.2 was never going to disperse to the kind of random abandoned WW2 airfields this implied. The high temperature requirement feels a bit extreme too, but I've not got a good feel on that.
It would be perfectly reasonable to assume that it would only ever fly from established airfields. This would allow accepting 2,000 yard runways - actually stated in OR.343 as normal - and a maximum LCN of 40. This is still a slight improvement on the Buccaneer (LCN 45) and was what was specified in OR.339!
That doesn't ease the avionics problem any, but it does mean that the solution space for the aerodynamics, structural, and propulsion design is a lot less constrained.