I'm sure it will be fine to take them on. You can explain that you will be taking a yet to be determined week off for your surgery, though. With the elementary students, you can just use your left hand more, and also be creative in "explaining" what you want them to do verses "showing" them. You can say put your right hand thumb on G and point to their thumb and point to G. You don't actually have to physically show them what it looks like.

Also, with these beginner students there isn't much "hands together" work so either of your hands will do the job. They will also learn that not only any finger, but any hand can play a note! (But of course, if you have 2 functioning hands like they do, they will have to keep playing it the written way. No exotic hand crossing playing for them yet ;\) . )

And with your more advanced students, they won't need as much demonstration as the beginners, and the demonstration they do need can be done with either hand by you, and they will be far enough along to transfer that information to their right hand.
_________________________
The biggest victories are seldom posted on scoreboards.