Thanks very much for the input so far, all - very much appreciated.
Having thought about it some more, I agree that Warlock definitely isn't worth it as a dip.
My DM won't allow Life Cleric + Goodberry, which I think is understandable since it does seem pretty crazy.
On further consideration Heavy/Medium armour proficiency don't seem as good as I'd originally thought, since there's no other reason I'd want to get 15 or even 13 Strength and it's not that much better than Mage Armour, but shield proficiency is still +2 AC and Bless/Command/Guidance/Shield of Faith/Healing Word are all really good.
I'm currently thinking Elf (Eladrin) Wizard with no dip.
Point Buy: 15 Int, 14 Dex, 14 Con, 12 Wis, 8 Str, 8 Cha.
16 Int/16 Dex after racials.
Cantrips: Minor Illusion, Mage Hand, Prestidigitation
Spells: Mage Armour, Find Familiar, Shield, Silent Image, Thunderwave, Alarm
My DM isn't a fan of Divination or Necromancy, so I'm thinking Abjuration at level 2 (with Alarm to recharge the barrier) but I can see Bladesinger or Theurgy potentially being good too.
What do you think? I'm kind of liking straight Wizard, but is Cleric 1 worth it?
e: One other idea which just occurred to me is just going Favoured Soul Sorcerer instead. It'd mean two sorcerers in the party, but it grants medium armour, shields and (with Life domain) access to Bless and Cure Wounds without sacrificing progression at all.