Sorcerer Gish Progression

[Quoz]

My character is currently a Dragon Sorcerer 6/Hexblade 1. I am looking at a decision point for my near term level ups between advancing Sorcerer for better spell progression or dipping further into Hexblade to allow a GWM build.

Important considerations:
Playing ToA (no spoilers please). So far we have been going mostly jungle exploration where we only have 1-2 encounters per day so I've been pretty liberal with spells so far. We will probably transition to more grinding dungeon craws soon. Twinned Haste, Fireball, Miror Image and Fireball are my go to combat spells. Most 1st level spell slots go for shield or convert to SP.

Our party has an unclaimed Flame Tounge Greatsword. I'm currently sword and board with a +1 longsword and can't use a greatsword unless I hit Warlock 3 for blade pact. My GM is ok with using twin on a Greenflame Blade. (Does the magic weapon extra damage apply to the adjacent creature's damage?)

The rest of out party is a frontline of Ranger and Rogue/Fighter, a utility caster Bard and a healer/utility Druid/Bard.

So now I'm at the point of either going for higher spell slots as a Sorcerer or delay by taking more Warlock to Gish better. Since Fire Bolt is almost as good as Eldritch Blast my Invocation selection is pretty wide open. So, higher level spells or invocations, short rest slots and better melee options?

[MephitBlue]

Tough question, basically trading a level 4 Sorcerer spell slot and an ASI for upgrading your Warlock spell slots to level 2, the invocations and pact boon.

My gut feeling is that if you want to focus on melee damage then go for the two levels of Hexblade next, if you are more spell caster focus, go for the Sorcerer levels. Delaying an ASI to take the next two levels in Hexblade has disadvantages for your character as well. You could use that ASI to take a feat like Warcaster to make it easier to cast spells while in melee and give you advantage on keeping concentration spells up or up your Charisma if it isn't 20 already to make it slightly easier to hit things.

I know my reply probably doesn't help much, but I'd base the decision on what seems more fun to you than which path is more optimal. Either path should be able to hold their weight in a fight.