Does seem weird, just got quotes on the Meerkat site with £100 voluntary excess & 10k miles a year for:
’23 plate Suzuki Across, 23k value, 323hp, £410 with AA (or £466 with Hastings Direct).
’24 plate Model Y Long Range RWD, £25k value, 384hp, £612 with Hastings Direct.
’23 plate Skoda Superb Sportline Estate 2.0tdi £23k value 200hp, £389 with Hastings Direct.
’24 plate Toyota Bz4X Motion RWD, £23 Value, 200hp, £415 with Hastings Direct.
All with 9 yrs no claims, but even with 3 years NCD, the BZ4x goes up to £475 on Hastings Direct (lowest quote £404 with Axa). Something seems very off for you to get quotes so sky high.
As for travel insurance, would never step foot out of the UK without it. I’ve never claimed but you are braver than me going to USA without insurance, small simple treatments can be astronomic without it, let alone major issues or repatriation costs.
In life, it's not who you know that's important, it's how your wife found out.