...to the Bennets next Christmas.

You have a particular vision of Charlotte's fate, but to most of your circumstances one could counter with more pleasant alternates (unless JA reveals something in the ensuing chapters). In reality we cannot speak with certainty of any of the characters' happiness in marriage unless JA continues her narrative until they are each in his or her grave. This is something I doubt she will do. Even where JA told family members privately about Kitty and Mary's eventual marriages, we do not know what happened subsequently.

Charlotte took her chance. How many stories weave around the dilemmas of those who suffer because they lack the courage to commit to a decision they feel is right--certainly as many as make the wrong decision. Likely Charlotte's life will have drawbacks, but (to avoid predicting P&P events) do we think after their marriages Emma and Knightley or Catherine and Henry Tilney or even Fanny and Edmund never suffered at least temporary difficulties, not to mention possible tragedies on the scale you predict for Charlotte? We hear from JA that Jane Fairfax lives only five years after her marriage to Frank Churchill.

Untold tragedies can happen to JA's happiest couples, but so can joys left unaccounted after JA brings her stories to a close. So we can never say whether Charlotte's life turns out as miserable as you foretell or whether she can at the last look back on her choice as the best available and source of much satisfaction (little of which is likely associated with Mr. Collins, LOL).