One group shot ? You mean just the bridal party + close family ?
I definitely take advantage of being inside and being able to control light more by using an off-camera flash + umbrella on a lightstand. If you can take 3 minutes to set up, why not do so and get far better results than shooting with ambient usually gives ? If the group shot isn't the one you go all out for with light control, then what photo is ?
I should add: if you know the church isn't so important for the couple and you know that you're doing group shots at a better location, then, yes, I'll probably shoot these with ambient possibly with a flash bounced off the ceiling. I avoid any lighting choices that creates harsh shadows behind the subjects at all times, however,