Nice winter conversion! 70-series tires would likely feel very plush indeed.
Duly noted on your less grippy tire / more driving fun proposition. In Miata-land, that I recently vacated, there was a similar feeling that slimmer tires (as suppled as stock) actually made for a more enjoyable driving experience most of the time (4-wheel drifts, "classic" sports car driving, etc.) versus gummy, wider tires that would skidpad to higher numbers or be better for autocross Sundays.