Can a character with the War Caster feat cast a Touch/5-foot range spell instead of making an opportunity attack with a reach weapon?

Question

This is a follow-up to an answer to a question about War Caster & Reach weapons. It is not the accepted answer, but it is the most upvoted one by a large margin so let's stipulate that yes, a War Caster may cast a spell instead of making an attack of opportunity with a reach weapon is true for the sake of this question.

The scenario

1. Waclaw the War Caster wields a reach weapon (a whip) and is able to cast Single-Target Touch Action spells like Inflict Wounds, as well as Single-Target 5-foot Action spells like Booming Blade.

2. Fred the Futile Foe is standing 10 feet away from Waclaw, and decides to move away from him, provoking an opportunity attack.

3. Waclaw decides he's going to cast a Single-Target Action spell instead of whipping Fred, as per the War Caster feat, but wonders whether Inflict Wounds and/or Booming Blade would be valid to use here. In this scenario, Waclaw does not have any additional ability (such as the Distant Spell metamagic option or the Spell Sniper feat) to increase the regular reach of his spells.

Can a War Caster (Waclaw) cast a Touch (Inflict Wounds) or 5-foot range (Booming Blade) spell instead of making an opportunity attack (towards Fred) with a reach weapon (whip)?

Logic would say "probably not" to me, but I don't know what RAW and/or RAI would say.

Answer 1

No, the range of the spells stays the same

The description of the War Caster feat (PHB, 170) says:

When a hostile creature's movement provokes an opportunity attack from you, you can use your reaction to cast a spell at the creature, instead of making an opportunity attack. The spell must have a casting time of only 1 action and must target only that creature.

The description of the Reach weapon property (PHB, 147) says:

This weapon adds 5 feet to your reach when you attack with it, as well as when determining your reach for opportunity attacks with it.

When the War Caster feat allows you to cast a spell instead of an opportunity attack, the range does not increase for your spells; you still cast a spell with a 5-foot or touch range, and creatures outside of that range can't be targeted by those spells.

Reach only increases the range at which you gain an opportunity attack. After that, you can choose to attack the creature with either your whip or a spell, but the creature is out of range for a touch or 5-foot range spell.

You could potentially use the sorcerer's Distant Spell metamagic option to increase the range of the spells cast, and then you could use them at that range.