Always better to be overdressed than underdressed for a social event (except maybe a rugby match in the mud) as it is easier to take off your jacket and ite than to skulk around trying hide the fact that you arent dressed to the same level as the average member of the party. I think that is especially so for kilt wearers entering into not traditionally kilt wearing community situations such as yours. The kilt looks better when worn with its more traditional accoutrements and is easier to explain and have accepted in that look, but then can be "undressed" or dressed down a bit as the event progresses if appropriate.

Example, at weddings most folks are still in their jackets and ties (just talking men here) when they get to the reception but may remove their jackets when they sit down for the meal, or may not. But by the time the cake is being cut and the dancing starts a lot moer of them have removed the jacket, tie, possibly the vest and maybe even rolled up their shirt sleeves (depending on the wedding) to partake more actively in the festivities.

I just think the traditional kilt looks better dressed appropriately in a designated social event and can be casualized down fairly easliy as you feel more comfortable with its reception among the group.