we are staying about 10 mins away from the terminal, the plan is for Jon to stay the night with us then drop us off in the morning at the terminal, I was thinking therefore about just checking in on the day. I wonder if i'll be missing out on anything if i don't do it? We won't be arriving at Gatwick until 7/8pm the night before. What do you think?

if we do do twilight check in how long before do we need to get to the airport?