I guess my point with that rather long-winded paragraph was to try and do as much as you can. If there is stuff you can do from a distance, then do it. Could you take over paying her bills online so that would be one less thing for them to worry about? Get there as often as you can to give the onsite caregivers a break and whatever you do, don't tell them that they're doing something wrong unless it would be a grave danger to your mother not to say something. When you are there, try and cook stuff ahead that can be frozen so that & portion it out into meal sized portions so that they can just heat stuff up. We always found that helpful when our friends around here did that with the meals they brought us. Quick & easy snacky type food is good to have around too...soup, cheese & crackers, nuts, protein bars....stuff people can just grab to snack on. While you're there, try and go through some of your mother's things and get rid of uneccssary stuff so in the event that life changes and she has to move, there's maybe a little less work. I did that while "sitting" with my DMIL, after clearing it with my DH and all his siblings. She was a hoarder of sorts, had a lot of crap...old pie tins, cheap plastic flower containers, wrapping paper pieces that wouldn't be big enough to wrap anything etc...so I would go through closets and cabinets getting rid of stuff that I knew was trash. If I found anything that I was unsure of with regard to its value (whether monetary or sentimental) I just set it aside in a box for her children to go through. When she passed and we sold the hosue, that made it quite a bit easier....
Excellent suggestions, Disney Doll.
npmommie, maybe being the nurse in the family they might like some help surrounding Mom's surgery since it's more your area of "expertise" than theirs? You know a lot of guys, especially, hate hospitals and the thought of Moms on bedpans, etc.

Maybe you could arrange to go around the time she'll be in the hospital and/or rehab? That wouldn't be unreasonable (though a couple of months certainly would, seeing you have young kids at home and a job, etc!). It might entail your DH taking time off as well, or soliciting other help at home in order to keep your own house in order while you go out with your Mom.
In my family, my mother lived quite a distance away from all of us. Even helping out regularly was difficult with work schedules, kids and such. As a family, we made the decision that having her come live with one of us would make the most sense in the long term, and being the nurse in the family (and the one daughter in state), she came with me/us (actually at DH's suggestion!). We built an in-law suite about 16yrs ago now and thankfully we did as she's aged remarkably since then but all of her needs are taken care of fairly simply. We do the lion's share but I if we need help, my siblings will help (we do have to ask, though, because they aren't really sure what to do, I think, since we do just about everything).
This arrangement hasn't been perfect, but overall it's been good. Where we live (and probably where you live), building in law suites became popular in the last couple of decades when housing, utility, and basic living costs soared and many elderly folks had difficulty making ends meet on their own. I have many friends who also have in law suites/elderly parents living with them and sometimes we joke we really ought to put a "support group" together as the challenges at times can be quite significant. But still, it's easier than trying to manage from a great distance IF (and it's a big if) the parties can all get along reasonably well living together.
Many folks either cannot afford the cost of assisted living or will refuse to go to live there. This thread made me think of a woman I cared for recently. She told me she was "ready to die" not because she was sick, but because she was "old" and "had nowhere to go". It broke my heart because she was adorable and full of spunk (someone I could see myself being friends with in another time and generation), but she lived alone at a distance from her family, and couldn't manage by herself any more. She had three children but they were "all busy with their own lives". Assisted living was an affordable option for her, but she was adamantly opposed, having led a fruitful and independent life all her life - so basically she was prepared to die rather than go there. Many will say, "her choice", which of course it is, but it still made me really sad. She celebrated a milestone birthday in the hospital and only one child came for a brief visit, the other two sent flowers.