Which is better a) travel/ stay w/my 86 yr old mom who lives alone to limit her outside exposure to COVID19 OR b) attempt care long distance?

I'm inclined to say wait and see for now, but keep your emergency kit handy in case you need to get there suddenly. The disabled adult - hopefully this person can be counted on to contact someone if there is a crisis?

Mom mom is healthy but the primary caregiver to a disabled adult. There is not a strong social network nearby to rely on except for a neighbor. She is not technically savvy so I would need to order groceries remote. She lives in South an I live in North, so I am a day’s flight away. My concern is whether by traveling to stay with her am I exposing her to more risk versus if she or the other family member were to get infected there would be no one there to help.

I don’t really know the answer to the question but if it helps, my mother has COPD, both her and my dad have serious health issues, they aren’t homebound and have my brother (who is battling alcoholism and is compromised himself) there but I am prepared to load up my kids and make the 6 hour drive to my parents house if need be. We are healthy down here with no confirmed cases in this county. My mom still has doctors appointments she needs to keep if possible. People are panicking in their town and clearing the shelves so.....I am ready to go up there and be chauffeur When they need to go to the doctor as well as drive all over tarnation looking for toilet paper and food! You haven’t given much info but if your mom is able to stay at home and you can arrange to have food and prescriptions delivered, you should stay where you are for now unless your mom needs someone there.

A lot depends on your locations, how far you have to travel, whether you're working, what conditions your mother has, how she's living now, etc. 

Your profile doesn't provide any of this background information, so any responses would be generic and not specific. 

Perhaps you could share more information on your situation.   Your question now is really quite general, so you won't be able to capture the benefit of the broad experience of the posters here.

It depends on how much care your mom really needs; if she's a spry, healthy senior who functions well independently, is comfortable using technology and has a big social network then she can probably weather this alone, but if she is in any way isolated, frail or confused she probably needs greater hands on supervision.