Luggage on US tours? Help, please!

I got my package for the Grand Southern the other day and am now a bit freaked about the luggage situation.

The GS tour only makes up about 35% of my total trip as I'll be going around Canada, more of USA and Europe before and after that tour.

Because of this extra travel before and after, I was initially going to bring my hybrid backpack (basically a backpack with wheels) as well as a small onboard plane size hand-luggage suitcase and a handbag/purse (for the valuables that need to be right on me at all times). This would mean that I could have one on my back, one being wheeled (hand-luggage) and one on my shoulder (handbag).

I know that during the Contiki tour itself I will barely be lugging my stuff around, but the rest of my trip is where it will matter as I'm using trains and planes every 2-3 days and I'll need to get to/from hotels and airports/train stations.

After having gotten the package, it says that no suitcases with wheels will be allowed onboard the bus, and only 1 suitcase is allowed in the hold.

Basically I wanna know, from peoples recent experiences, if anyone has ever:
*Taken hand-luggage size suitcases (with wheels) on board a Contiki bus?
*Taken more than two suticases into the hold?
*Any other information you want to provide about the luggage situation when your tour began? Did your luggage even get checked?

My backup is to take a duffel bag instead of the hand luggage size suitcase but carring that on my shoulder while carring a handbag on my other shoulder AND a backpack on my back is near impossible (trust me, I just tried it, it weighed barely anything and was difficult).

I know either way that I will be well under the 20kg limit as the tour is the toward beginning of my entire trip.

Thank you to anyone who can provide any advice!