My TIG is about 15 feet from my mill controller (PC based) and I do run both at once - TIGing Aluminum at that. No problems going on almost two years.
I have heard of people claiming the TIG HF screwed up their cell phones and interfered with their radios and remote controls, but I have never had these issues. The chassis of the welder and the control cabinet are both grounded - that might be the reason I haven't seen any issues (?) .