You can take the mana forge cantrip and generate mana from gold. Also there are cantrips to help your odds and you can also come up with advantages or disadvantages on the environment to reroll in your favor or the monster favor during combat.
For the items remember to roll 1d6 starting mana for each, that will get your mana pool a bit more stocked. But I will look into modifying the card rule so in case you get a high card and loose a roll it's not instant defeat at level 1. The idea of replenishing the items, personal and familiar mana at each days sounds plausible and more reliable, I think I'll add that in.
As for my gameplay, I think I've been lucky so far and haven't had these scenarios happen the several times I played