Whether 3300 c.i. is big enough will depend entirely on the bulk of what you need to fit in it.

To answer your question, we can only use the few facts you've told us (5 day trip, tarp instead of a tent, minimal water) and that really isn't enough information to do anything but make an offhand guess. Heaven knows, some sleeping bags are much bulkier than others. The bulk of the clothes you bring, and food bulk can be just as capricious. For all we know, your sleeping bag, clothes or food could be almost any size.

I presume you already have most of your gear available to you to put in your pack, so the first step is putting it in your pack and looking at how much room is left. If it is filled up before your food goes in, you'll need to make adjustments, either smaller gear or a bigger pack.

It's hard to say much more than this. Sorry.