Uh....I don't see everyone saying or assuming that.
Oh, sorry. I missed that one.
Considering the number of background stories where characters were traveling as babes but ran and hid while their parents were slaughtered, I'd be more worried for Solas and Lavellan. The kids would be fine; some Dalish clan or kindly knight/merchant/farmer will come take them in and help them grow up strong so they can get revenge/try to live a normal life/attempt find their place in the world.
Solas and Lavellan, though? Man. Rotting on a forest floor somewhere, or scattered to the winds as nothing more than dust and bones. That will teach them to travel with kids!
I think the Dread Wolf and former Herald of Andraste can handle it. 
Although, when you think about it we've found just as many orphans whose parents died horribly who come from sedentary lifestyles too, so, pick your poison.
I would also argue that I wasn't the first to bring up the travel around stuff being an issue. In my initial post I said I didn't see Solas as a dad type in so much as actually wanting kids of his own. For me that means staying at home or dragging them every where with you. Doesn't matter if you are in a white picket fence or traveling in a caravan your lifestyle is going to change when you have kids. There are going to be things they just wouldn't be able to do anymore. Tiny example Solas thinks hey Lavellan lets go into the Fade and find memories in this place except now you have a screaming toddler who doesn't want to take a nap nap right then and has no interest in the Fade at that moment. So never mind.
Just play catch or tag with the kid for an hour, they'll go out like a light. 
In all seriousness, I understand where you're coming from, I just don't fully agree. To me, "your lifestyle is going to change" doesn't mean "You can't do any of the things you want to do anymore!" Okay, so Solas will have to schedule his Fade visits around his kid's sleep schedule. No biggie. Even if little kids don't nap on demand, they still have to sleep sometime, and when they do... Okay, so Solas and Lavellan can't go into war zones anymore--although, unless they're still part of the Inquisiton, why would they be in war zones or hunting evil in the first place?
And if they are still part of the Inquisition, technically they have babysitters on hand all the time anyway...
I guess it just depends on what you're fantasizing and what kind of lifestyle you envision for your Lavellan and Solas. For some, they imagine a possible AU happy ending in the future where the Inquisitor convinces the Dread Wolf to lay down his burdens, but they know Solas is never going to be accepted by modern Thedas after the stunts he tried to pull as the Dread Wolf, so they'd probably have to quietly retire somewhere anyway. For some, they imagine a happy AU where Solas chose to discard his plans during the culmination of the romance, so if Solas already gave up his ambitions as the Dread Wolf and/or his immortal lifestyle of wandering the Fade in Uthenera to settle down and live a mortal life with Lavellan, a domestic life with kids is not too far off. Some might also see them as staying with the Inquisition for years, where they have a huge social support network of companions and Inquisition employees to serve as round-the-clock babysitter access. However, some, like yourself, see them as continuing adventuring and confronting/fighting bad guys, so now that you mentioned it I can see how kids would definitely not work in that circumstance. (Not to mention there's no kids in Uthenera situations, unless there's a way for spirits of sleeping mortals to reproduce little spirits in the Fade while their physical bodies sleep in the real world...)
Again, it all depends. I guess I just personally don't understand arguments like, "having kids = mandatory boring domestic lifestyle" or "having kids = you can't do any of the things you love anymore because you now have to schedule things you want around caring for your kid's physical needs" because I don't see it that way.