Ég myndi fara með henni aftur, þó að við þyrftum að bera tvo bakpoka og fleiri vatnsflöskur.

Myndi is the conditional form of munu and is often used like English would.

So ég myndi fara means I would go, not simply I go or I will go.

In Icelandic, this kind of form is very common when the speaker is talking about:

• a hypothetical situation
• willingness under certain conditions
• something that is not being stated as a plain fact

Here it gives the sentence a conditional or tentative feeling.

Because með means with, and prepositions in Icelandic control specific cases.
The preposition með takes the dative, so hún becomes henni.

The basic forms are:

• nominative: hún = she
• accusative: hana = her
• dative: henni = her
• genitive: hennar = her / hers

So:

• með henni = with her

Yes. In this sentence, fara með henni means go with her.

A learner should be aware that fara með can mean different things in other contexts, for example:

• handle / treat
• sometimes part of other idiomatic expressions

But here the meaning is simply the literal one:

• fara = go
• með henni = with her

So together: go with her.

Aftur usually means again or back, depending on context.

Here it most naturally means again.

Its placement is normal. Icelandic adverbs like aftur often come after the verb phrase or after the object/prepositional phrase, depending on style and emphasis.
So Ég myndi fara með henni aftur is a natural way to say I would go with her again.

Þó að means although / even though.

It introduces a subordinate clause that expresses contrast:

• I would go with her again
• even though we would have to carry...

It is a very common conjunction in Icelandic for this kind of idea.

This is one of the most important grammar points in the sentence.

Þyrftum is the past subjunctive form of þurfa for við = we.

It appears here because:

1. þó að often triggers the subjunctive
2. the whole sentence is hypothetical/conditional, because of myndi

So Icelandic uses a form that matches that non-factual, conditional tone.

Compare the idea:

• við þurfum = we need / have to
• við þurftum = we needed / had to
• við þyrftum = we would need / would have to or a subjunctive/hypothetical had to

So þó að við þyrftum fits the meaning even though we would have to.

Because in Icelandic, just like in English, past-looking forms are often used for hypothetical meaning, not only for real past time.

English does this too:

• I would go
• If I had time
• Even if we had to carry...

These are not always about the past. They often express unreality, tentativeness, or condition.

So in this sentence:

• myndi is not simple past
• þyrftum is not simple past either

Both help create a conditional, non-literal-now sense.

Because þurfa is followed by an infinitive.

So:

• þurfa að bera = need to carry / have to carry

Here the finite verb is þyrftum, and bera stays in the infinitive.

This is very common in Icelandic:

• ég þarf að fara = I need to go
• við þyrftum að bera = we would have to carry

This shows both number agreement and case.

1. Why tvo?

Bakpoki is a masculine noun.
The number two changes form depending on gender and case.

For masculine accusative plural, the form is tvo.

2. Why bakpoka?

Bera takes a direct object, and here that object is in the accusative.
The accusative plural of bakpoki is bakpoka.

So:

• tveir bakpokar = two backpacks as a nominative subject
• tvo bakpoka = two backpacks as an accusative object

That is why the sentence has bera tvo bakpoka.

Fleiri means more. It is the comparative form used before plural nouns.

Vatnsflöskur is the plural of vatnsflaska and here it is also in the accusative plural, because it is another direct object of bera.

So:

• fleiri vatnsflöskur = more water bottles

A useful point:

• fleiri is often the same form across several genders/cases in actual use
• the noun still has to appear in the correct form

Here the structure is:

• bera tvo bakpoka og fleiri vatnsflöskur

Both noun phrases are objects of bera.

Because Icelandic often leaves nouns indefinite unless there is a reason to make them definite.

So:

• tvo bakpoka = two backpacks
• fleiri vatnsflöskur = more water bottles

If the speaker meant specific known items, Icelandic could mark definiteness differently, often with the suffixed article. But in this sentence the nouns are just indefinite.

Yes, it is completely normal.

The clause begins with the conjunction þó að, and then follows ordinary subordinate-clause order:

• þó að
• við
• þyrftum
• að bera...

This is different from the main clause, where Icelandic often shows verb-second word order.

Main clause:

• Ég myndi fara með henni aftur

Subordinate clause:

• þó að við þyrftum að bera...

So the sentence is a good example of the difference between main-clause and subordinate-clause structure.

The dictionary forms are:

• myndi → munu
• fara → fara
• þyrftum → þurfa
• bera → bera

A learner may especially want to note these:

• myndi comes from munu, which is irregular and often used for future or conditional meanings
• þyrftum comes from þurfa, and the vowel change is part of the subjunctive pattern

So this sentence contains forms that are not always easy to recognize if you only know the dictionary entries.

A few pronunciation tips:

• þ is like English th in thin
• ð is like English th in this, though in some positions it can be weaker
• þó sounds roughly like thoh
• að is often pronounced lightly in normal speech
• þyrftum is harder: the yrf cluster can feel unfamiliar, and the u in -tum is short

The most important thing is not to pronounce:

• þ like plain t
• ð like plain d

Even an approximate th sound will help a lot.