Can I Avoid Using Flash at a Wedding Ceremony?

Dear Jasmine
A couple hired me on a budget, so I'm working with what I have and don't have a lot of financial room to rent. Basically, the venue is beautiful. Lots of garden. Lots of exposed brick and antique mirrors – it's great. The ceremony is outdoors and the wedding planners are firm on starting the wedding at 4:30pm. Sunset is at 5pm. There is very little external illumination. Some strand light bulbs hanging and some LED's bouncing off the greenery.
I'm concerned about photographing a ceremony at DUSK with very little ambient light. I have a few flashes, but I've never been a huge fan of using them and I have no idea what their behavior will be like from 30 feet back at the ceremony. I've urged the wedding planner to start the wedding 30 min earlier – as it is completely dark by 5PM in January. The couple seems fine with it. But, the wedding planners don't.
Do I push the couple to change the wedding planners' mind or do I suck it up and try to solve it as best as I can with my flashes? I really don't want to start any trouble as I'm not a full time wedding photographer and I'm really just trying to get my friends the best photos I can get for them. Any thoughts?
Just Trying to Help

Dear Just Trying to Help,
Firstly, I applaud your kind heart and wanting to help your friends…I'm sure they're thankful for working within their budget.

Secondly, I need to address something you didn't really focus on: you not being a “fan” of using flash. There's a difference in not liking the look of flash, and not knowing how to use flash. If you don't like flash because it intimidates you, then I'll be honest and let you know you need to learn how to use it. Like, now. Given this situation (and any wedding at sunset), you must be fully confident and prepared for whatever light situations come your way. Sure, it's not ideal, but as a wedding photographer, you need to work like a professional (regardless if you're full time or not).
I suggest practicing with your on-camera flash extensively for the next month (practice for 15 minutes every day in different light situations) so you can get a feel of how you'll need to work at varying distances from your subjects. I realize you're doing your friends a favor, but they're trusting you to capture their day professionally…and my professional advice is to get really comfortable with your flash. It'll be your best friend or worst enemy on the wedding day.

Lastly, if a wedding planner is reluctant to change the time of the ceremony, then I wouldn't push the matter. If you asked to change the ceremony time and she said no (or didn't respond at all), it'd be in your best interest to let it go. The last thing you want is to be at odds with the coordinator before the wedding arrives. In light of this, practice with your flash (and, if possible, with an off-camera flash too) so you can leverage the light it provides. If you need help, these flash-related posts will assist with your learning curve.

Just Trying to Help, I really hope things go well for you…if you dedicate yourself to being prepared, you have nothing to fear.