Brexit alert: £350 a year for travel Insurance

Loss of European Health Insurance Card will cost  me £350 per annum

I have reached that age when my bank will no longer provide free travel insurance so I was urged to take out some travel cover. Saga was too expensive, presumably because of the greater probability of claims by the oldies, so I found insurance from another bank that was £68. Then I was told that it would rise if we left the EU and we no longer had the European Health Insurance Card. I was quoted £350 per year. Now where have I heard that figure before?