Simple examples for anyone struggling:

1. Conditional:

Basketball players are athletes

Tom plays basketball

---

Tom is an athlete

2. Contrapositive:

Basketball players are athletes

Tom is not an athlete

---

Tom does not play basketball

3. Conditional Chaining:

Kittens are cats. Cats are cute

---

Kittens are cute

4. Some before all:

Some cats are pets. (All) Pets are kind

---

Some cats are kind

5. Most before all:

Most cats are pets. (All) Pets are kind

---

Most cats are kind

6. Two Mosts:

Most cats are pets. Most cats are kind.

---

Some pets are kind

A source of confusion for me is how the term "on very cold days" is interpreted in question 5.

Could the sentence be rephrased

(A) "On very cold days, at least 59 percent of households maintained a lower indoor temperature than they had been accustomed to maintain"?

Or

(B) must the "on very cold days" be read only as part "accustomed to maintain on very cold days"

This would change the meaning of the sentence. If we interpreted it as A, then it would mean that the comparison looks like this:

1. very cold days vs accustomed to (assumption: on not very cold days)

2. indoor temperature (which is lower?)

3. winner: very cold days

i.e. The indoor temperature on very cold days is lower (for 59% of households) than the indoor temperature they are accustomed to (assumed, on not very cold days)

If we interpret it as B, then the comparison goes like:

1. Accustomed to (descriptive: on very cold days) vs. Now

2. indoor temperature (which is lower?)

3. winner: Now

i.e. The indoor temperature is lower Now (for 59% of households) than they are Accustomed to on very cold days

My problem is that this grammar leaves room for error in how we understand "on very cold days". Is it a descriptor, which narrows our understanding of "accustomed to" to mean only "what they are accustomed to only on very cold days (but not what they are accustomed to on days that are not very cold)" or does it modify the entirety of the sentence and thus make the comparison very cold days vs what households were accustomed to (on not very cold days)?

Both my interpretation (A) and the interpretation in the video (B) require us to make an assumption. (A) makes the assumption that "accustomed to" implies "on not very cold days." (B) makes the assumption that we are comparing "accustomed to on very cold days" to "now." The assumption in (B) seems to me like a greater leap than the assumption in (A), making (A) a more reasonable way to read it.

Am I misunderstanding a grammar rule that would eliminate the possibility to interpret the sentence as (A)? Would there have to be a comma after "maintain" in order to read it this way?