I wouldn't buy the "dream" bike first. Get something small (safe) to ride around on first and do some short trips to make sure you really want to do this.
And quite frankly that is the appeal of the Hondas.
Practical. Reliable.
Less expensive. Lots of dealer support. May not hold resale value like a BMW with a boxer engine, but it also costs less, weighs less, and while less capable off-road that should not be an issue. We are not looking to cross Africa or Mongolia or take logging roads through the Amazon. We are looking for fun, comfortable, easy to ride for a summer adventure.
I could outfit one of those Honda NC700x bikes, with cargo boxes, helmet, leathers/rain gear, communications, etc for under $15,000. The "dream" BMW would be right under $30,000. Sure the BMW would offer lots more power, lots more capability, but being honest about all this I'm a "scooter" guy. Love to run around on the scooter, enjoy the rural roads, but I don't need to make
a giant leap for mankind just to go on a summer vacation.
And I need to think about the budget here because I'd be buying not 1, but 3 of these things, plus the cost of the trip itself (food/lodging). Even if we decide to sell after the potential trip I'd be better off with 3 lower priced, capable bikes than 3 ultimate dream machines.
The Honda pictured below is the Africa Twin. It is 1 model up from the NC700x. Its about $3000 more in cost, bigger engine that is well suited for a long trip.
But its about 535# without the cargo boxes. Not sure that would be as easy to handle for the Lovely Mrs_Bob and Melen. Given Melen's back surgery I am somewhat concerned about going up in weight, and I think that is a very justifiable concern.