Why would David Copperfield need to change lodgings when the Micawbers leave London?

Question

In Dickens's David Copperfield ¹, when the eponymous character is despatched to work in London, his stepfather Mr Murdstone arranges for Mr Micawber to take David in as a lodger (p. 148). Soon thereafter, Mr Micawber is imprisoned for debt. The Micawber family gives up their rented house to move into the prison with him, and David gets a room nearby:

Mrs. Micawber resolved to move into the prison, where Mr. Micawber had now secured a room to himself. So I took the key of the house to the landlord, who was very glad to get it; and the beds were sent over to the King's Bench, except mine, for which a little room was hired outside the walls in the neighbourhood of that Institution, very much to my satisfaction.       (p. 157)

Upon Mr Micawber's release from prison, the family decides to move to Plymouth (p. 162). David therefore decides to run away from London:

I had grown to be so accustomed to the Micawbers, and had been so intimate with them in their distresses, and was so utterly friendless without them, that the prospect of being thrown upon some new shift for a lodging, and going once more among unknown people, was like being that moment turned adrift into my present life, with such a knowledge of it ready made, as experience had given me. All the sensitive feelings it wounded so cruelly, all the shame and misery it kept alive within my breast, became more poignant as I thought of this; and I determined that the life was unendurable.       (p. 163, emphasis added)

It is understandable that facing friendlessness and hardship in London, David should decide to run away. What I don't understand is the emboldened clause above. David already has a room of his own; he is no longer living with the Micawbers. So: why would the Micawbers' leaving London for Plymouth necessitate David's having to find new lodgings?

To speculate a bit on the hero's resolve: Certainly Mr Micawber's release from prison gives David a convenient cover story for escaping London. He can tell his present landlord that no longer needing to be near the prison, he wants to move somewhere else, closer to his workplace for example. That way, the landlord would not realize that David is intending to leave town and so thwart his flight. We learn that David's "box" (i.e., the trunk with his belongings) is still at the house previously rented by the Micawbers (p. 168), but the same principle applies: with the Micawbers no longer living there, David will need to take his trunk elsewhere sooner rather than later, so the prior landlord has no reason for suspicion either. And indeed, David does leave London without being stopped by either landlord. But the quoted passage says explicitly that David would need to find another lodging, not merely that he could feign wanting one, and since he already has his own rented room, I don't understand why.

      ¹ _{Dickens, Charles. David Copperfield. 1850. Introduction by David Gates. Notes by Nitin Govil. New York: Modern Library, 2000.}

Answer 1

David's ability to control his own lodgings at this point in the story is limited, because he is eleven years old (give or take) and his stepfather Mr. Murdstone is footing the bill. The nature of this arrangement is laid out in Chapter 10, when Murdstone ships David off to work at his business:

Mr. Murdstone, with an impatient, even an angry gesture, resumed, without noticing what he had said:

"Those terms are, that you will earn enough for yourself to provide for your eating and drinking, and pocket-money. Your lodging (which I have arranged for) will be paid by me. So will your washing—"

We then find out that Murdstone sent a letter to Mr. Micawber, with whom he has a minor business connection, asking him to receive David as a lodger.

When the Micawbers later follow their patriarch into debtors' prison, it is presumably not David himself who arranges for his alternative lodging. Note the passive-voice construction: "a little room was hired", not "I hired a little room". The Micawbers are still responsible for housing David under their arrangement with Murdstone, even if they aren't directly providing the housing themselves. Perhaps they're subletting.

But when the Micawbers leave the city entirely, it breaks the arrangement. This means the responsibility for arranging a new lodging falls back to Murdstone—or, in his absence, his employee Mr. Quinion. And indeed, David is not permitted to stay in his existing lodgings, just as he'd predicted.

Mr. Micawber himself came down to the counting-house, in the afternoon, to tell Mr. Quinion that he must relinquish me on the day of his departure... And Mr. Quinion, calling in Tipp the carman, who was a married man, and had a room to let, quartered me prospectively on ​him—by our mutual consent, as he had every reason to think; for I said nothing, though my resolution was now taken.

Granted, Quinion could have chosen to let David stay at his existing lodging. But given everything David's been through, you can hardly blame him for being pessimistic on that point, especially if neither Murdstone nor Quinion had a personal connection to that particular landlord.