Sorry, but this is gonna be relatively short. As per my recent IC post, the only ways I see per the VtR 2E rulebook to regain WP are via Mask/Dirge, and protection of the Touchstone. Neither resting a night, nor the start of a new game session is listed as a way to regain WP (at least as far as I could see).

As per that IC post, I am happy to house rules this if everyone feels strongly.

Cheers!