And regarding family support (which many of you have mentioned) ...
I grew up in a travelling and cycling family and a family who supports each other in whatever we do ... and they understand my passion for cycling and travel. The older I get, the more I appreciate how I was raised.
Fortunately, I met Rowan who is also into travelling and cycling and so we do all that together.
My parents are getting up there in years and my mother has certain health issues so she isn't able to cycle outside much anymore. I think she gets out on the Cattrike now and then, and rides her indoor recumbent, but that's about it. My father, however can still cycle and does get out for rides several days each week, and that's OK with my mother. She knows it is beneficial for his health to ride.
But even when they could both ride outside, because they rode at different speeds and strengths, they compromised. They either rode their tandem together ... or they made route compromises.
For example ... We did a lot of hub-and-spoke style tours growing up ... my father might head out early in the morning from the cabin we happened to be staying in, then my mother, brother and I would set off. My father would turn around at a designated point, and would meet us on the way back, often at a tourist attraction or something. Then we'd all cycle back together. That way, we could all get the rides in that we wanted.
So yes, as some of the others have mentioned ... have a good discussion with the GF and see if compromises can be made. You just never know.