Travel CPAP and Traveling Light

What "recommended limits" are you referring to?

Basically, you just need to handle your own luggage. I put my CPAP, and more in an "international" carryon size backpack with wheels, and check a 22" bag. I've used this method on 5 RS tours with no problem.

Weights recommended by Rick Steves and company?

Sometimes a traveler has to modify Rick's advice.

I may need to investigate further, yet what is the international carry on allable size? Ian trying to avoid checking any luggage

Carry on limits are not suppose to apply to medical devices and supplies. You could board with your carry-on, a personal bag AND your medical device ina third bag. You would just have to be able to handle those items. If you carry-on had back pack straps and your personal bag an cross body over shoulder strap, you would have two hands free to carry your bag with your device.

We've never taken a RS tour, but I've packed my husband's cpap in carry on only for 5 international trips. We put the hose and mask on top of his clothes in a roller bag and put the motor in one of our "personal items". He doesn't use a humidifier but we do take an extension cord. The roller bag usually weighs about 20 pounds. It can be done.

Airlines within Europe usually require smaller carryons than American companies flying to Europe. You don't necessarily need to meet those requirements if you are not flying within Europe.

There are suggested limits for RS tours, but as I said above, as long as you can carry your own luggage without help, nobody will care about the size.

I don't usually have to make connections when flying, so I'm fine with checking a bag.

Remember you also generally get a "personal item" to put under the seat if you want to do carryon only.

Maybe there is something here to help:
https://www.ricksteves.com/travel-tips/packing-light

Are you referring to the line "my self-imposed limit is 20 pounds"? Just because he self imposes it on himself doesn't mean you have to. Did you notice those young people in the website photographs all are wearing the backpacks on their shoulders? Is that you? Is that what you're trying to do? Or are you a seasoned in years (old) person like the rest of us?
If I recall reading elsewhere on the site, RS or some other travel writer doesn't recommend the backpack/combo option, because he ( or whoever writes the articles) has found nobody ever uses the backpack straps. They just wheel the luggage around all the time.
IMHO, getting you luggage down to 25 pounds is amazing! Pat yourself on the back! That will be easy to wheel around and carry up and down stairs.
As for my CPAP, I use the HDM Z1, which is 10 ounces. Add the mask, hose, power supply and power outlet adapter, it comes to about 2 pounds in a 9x7x4 soft pouch container.
Have fun on your trip!

My carryon has been discontinued, but is similar to this:
https://www.eaglecreek.com/shop/wheeled/expanse%C2%A0convertible-international-carry-on-ec0a3cwj?variationId=227#hero=0

Perfect for rolling through airports, and I put it on my back when I need to pull my 22" bag at the same time.

yet what is the international carry on allable ( allowable) size?

Varies by airline. You will need to read the baggage policy for each airline you plan to use

I guess that I am settling my bar pretty high. I have travelled like that before. That’s more bags than I really want to juggle at one time. I know that I can do that, yet I’m trying to minimize the number of bags and weight. I spent three months in Europe with an external frame backpack. I don’t have that kind of time anymore, and want to minimize the burden.

My husband uses a Philips Respironics CPAP which has a dual-piece humidifier and main section. He leaves the humidifier at home when we travel.

We both each use a roller carry-on size suitcase, and he brings a normal backpack, and I bring a small daypack. We do pack light - 3 or 4 outfits each and minimum stuff. He packs his CPAP in the backpack, with the hose in the roller bag. The first year we traveled with his CPAP, he had it in a separate rectangular bag (okay because it is a medical device). He hated carrying that extra bag, and it was clumsy since it didn’t sit stable on top of the carry-on when walking or catching trains.

I was 24 when I made my first trip to Europe. Times and I have changed a lot. I’m am still able to carry the loaded convertible suitcase/backpack even though I am “older”, so I don’t want three bags hanging off me as I walk through airports, Train Station or roads to the hotel

I’ve been in this bind when 1/2 of my carry on was filled up with binders. You may be able to make more room by lightening the clothes and other stuff.

Snarky Nomad travels with a 25 L pack. That should give you an extra 15 L for the CPAP equipment in your main bag. Or perhaps you can offload clothes into your personal item to give more room.

I’d recommend these two articles

Backpacking through Central America

Ultralight Packing List

BTW you don’t list the weight of your roller bag. It should be 5 lbs or less.

Doesn’t your C-PAP have it’s own carrying case? It does not count as a piece of your carry on limit as it is a medical device.

My husband uses a Philips Respironics CPAP which has a dual-piece humidifier and main section. He leaves the humidifier at home when we travel. We both each use a roller carry-on size suitcase, and he brings a normal backpack, and I bring a small daypack. We do pack light - 3 or 4 outfits each and minimum stuff. He packs his CPAP in the backpack, with the hose in the roller bag. The first year we traveled with his CPAP, he had it in a separate rectangular bag (okay because it is a medical device). He hated carrying that extra bag, and it was clumsy since it didn’t sit stable on top of the carry-on when walking or catching trains.

If you do a forum search, you'll find multiple threads about CPAP travel. I've addressed it several times. My experience has been very similar to what Jean references above. Juggling the third bag was a huge PITA for me. I also now leave the humidifier at home and I pack the CPAP in my Euro Flight Bag personal item, which goes under the seat on the plane.