EF, you won't necessarily gain if you save syns. You did last week, but that was when you saved them up and still went over them, and it was also on the day immediately before weigh in. So bad timing didn't help you!
Saving them can work (to a certain extent) - but if you've saved them, you still need to stay within your saved total.
Or else have a flexi day, because it's a funeral and you will be struggling emotionally.
But even if it's a flexi day, say to yourself that you're allowed, say, 40 syns - but you must still count them.
So long as you don't get into the mentality of "flexi-syns = day off = do as I like and don't count it", and so long as you only take that one flexi day, you should still lose, taking the week as a whole.
It depends whether you think you're going to be strong enough to deal with the funeral on a standard 100% On-Plan SW day with just 15 syns.
If so - go for it.
If not - think about what is the least worst of your other options?
I know this is your first week of being back on plan, and you want to be 100% as much as possible, BUT - you don't have your grandmother's funeral to deal with every week.
It's good that you're thinking about it now, though. It's important that you get through that day as well as you possibly can, and if that means that SW isn't at the absolute forefront of your mind, for that amount of time only, then you need to have pre-planned how to deal with it.
I hope it goes well, and that it doesn't derail you.