The party, which includes a bard and a wizard both with counterspell, will soon be facing a marid. The marid's total time on the battlefield will likely largely depend on whether or not he is able to get off his conjured water elemental to act as a blocker.
The marid has Innate Spellcasting with conjure elemental at 1 / day. I am assuming the " 1 / day" is what the MM refering to in this case when it says (p. 10):
An innate spell can have special rules or restrictions.
The marid plans on leading with fog cloud to either obscure his subsequent casting or draw any initial counterspells, or simply flying out of range, but either way it is still possible that at least one of the resourceful party members will be able to counterspell his conjure elemental. If that happens, does he get another attempt or is he done? Can he keep trying until he is successful?
Does the 1 / day restriction on conjure elemental limit the marid to one attempt, or one successful cast, per day?
The preponderance of opinion on this site is that a countered spell costs the caster the slot, although I find it hard to believe that we don't even have a Sage Advice ruling on that. If your answer to this question depends on whether a countered spell still costs a slot, it probably would be best to make that assumption explicit.