If an elderly person is unable to get to Mass on her own and does not have transportation, there is just reason to miss Mass. You may want to find out if your parish has a ride-sharing program for otherwise homebound parishioners who need rides. If so, perhaps you could arrange for a ride for your mother when you know you will be out of town. If not, you could ask an EMHC to the homebound to bring your mother Communion at home that week. As for a televised Mass, it does not fulfill the Sunday/holy day obligation, but it can provide a means to participate in the Mass in some way for those who cannot attend Mass in any other way.