It won't be horrible but there will be withdrawals. I find the fear ends up being greater than the reality though.
You have a few things going for you. You're experienced, and you have a taper plan, and you seem to respect that.
So how can you make it even easier? Can you stretch a 6 day taper to 8 or 9 days? I use a calendar and literally plot it out. Potentiate naturally to help with this. Play any games you can to stretch it. If you wait 8 hours to dose, wait 9 or 10 hours. If your dose is 4mg, try 3.5 and save the other half a milligram. When you feel like withdrawals are coming on, go out for a long walk, exercise, take s hot bath, anything you can do to wait as long as you can. At night, try taking a lower dose but add a sleep aid like nytol (or half of one). If you get up in the middle of the night, try a nytol or 2 instead of dosing.
Drink detox teas in between doses, start cleaning yourself out. Try oral instead of sniffing, especially for a bedtime dose.
If you can get just a little bit of suboxone, and when you finish all of your dil, wait as long as you possibly can (48 hours?), and take hust enough suboxone to help, you should already be in much better shape, im talking maybe 1 milligram, but immediately taper subs, going from 1mg to 0 in like a week. Even 1/4mg, 1/8milligram in the final days.
And, know that you can do it, trust the process, and that it will be alright.