Filters - My DME sends me a lot of these. Little packets of 2 each. I only use one so I have a lot left over. I put in a new filter before I leave and another new one when I return. If a hotel is smelly and I move to another hotel or wherever, I change it again. The filters stay in my bag even when I am home. That way I know where they are! I do, however, leave all but 2 packages at home when I leave.
medical information - I added this for my last trip. It is not to show to the Security Powers That Be but for in case I have a medical emergency away from home. My CPAP settings are listed as well as the number of my doctor and my DME. It's on a simple print out I made and then cut off the excess. It and the filters go into the outside pocket of the bag.
extension cord - I got a 6' cord from Lowe's that has a flat end. This enables it to be put in that well hidden outlet behind the mattress. Usually 6' is too long but you never know where the plug will be in relation to where the machine will be! I don't use this cord for anything else and it stays in my bag. In looking for an extension cord, look for at least a 16 AWG cord. Go for the smaller number in the AWG vs a larger number. Anything less than 14 AWG, though, may be too bulky for the typical CPAP bag.
surge protector - I have a cool one I got primarily for my laptop but keep it in my CPAP bag when I travel. It has just 3 outlets but also has 2 USB outlets. Belkin's product # is BST300bg. I got mine from Cyberguys. Their SKU # for it is 112 0152. BestBuy doesn't carry it. The plug end swivels so it can be at different angles, a handy thing in hotel rooms with scarce and oddly placed outlets. I was able to run my CPAP and keep my phone (with it's alarm) near the bed. Typically hotels have decent power with few fluctuations but it never hurts to use a surge protector! I especially use it if I have to also use the extension cord. This one does not stay in the bag when I am home. I use it a lot with my laptop when in cafes and the like.
Liberator Plus - this is a cool short cord. It plugs into an outlet, has a "pass through" outlet, then an short extension cord with yet another outlet. This is great for low draw computer equipment. Since hotel outlets can be anywhere, this allows you to use one outlet for 2 things. I've used it before I got the surge protector and will use it in places where the surge won't fit. I've used it for when a lamp needs to be left plugged in yet I needed the outlet. They are made by Ziotek. Their product number is ZT1212510. Cyberguys item # is 121 2510. I keep one in the bag at all times.
bag tag - eons ago I got a "medical equipment" plastic tag for my CPAP bag. It was on sale with one of the online suppliers. No one has ever looked at it or asked about it. I just say "This is my CPAP bag" and that's that. But it is nice knowing I can look at the tag and spout off the rule numbers. This is attached to the CPAP bag handle.
And yes, it all fits in the bag. When I had the Breeze mask, it didn't all fit. I could only carry the extension cord, which, of all of them, I consider the most important.
The main thing I wish I could change is a shorter CPAP hose. With the 6' extension cord and the machine's 6' or so power cord, I don't also need a 4' hose. If the machine is still not close enough, I'll go to another hotel! A shorter hose would also take up less room in the bag. And in that vein, I wish CPAP bags were larger. Yes, there's room for the machine and it's cord but, really, that's it. The bag for my old S7 barely had room for the cord!
Take a deep breath and count to zen.