The sauce keeps 5 days refrigerated and freezes 3 months — a double batch is the same work. Dressed pasta doesn't store well, so keep sauce and pasta separate if you expect leftovers.
Canned tomatoes are acidic. A pinch of sugar, a grated carrot, or a longer simmer all round it out. Don't use baking soda — it flattens the flavour.
15 minutes gives a bright, fresh sauce; 45 minutes gives a deeper, sweeter one. Both are correct — they're just different sauces.
About 4 oz (115 g) dried per person for a main course.