Life happens and Ein will adjust. He is lucky that your mom can watch him several days and some of my dogs have been crated for 9 hours once a week with no problems. I would make sure either he has a big enough crate and toys or you could try an exercise pen also. Many dogs do this everyday so both you and Ein are lucky for the little bit he has to be crated. I know that we sometimes (at least me) feel worse for the dog than they probably feel.
I used an xpen in the kitchen if I knew I was going to be gone quite a while, that way he at least had a little room to move around and could look out the patio door. I left Luke penned for ~8 hours sometimes when he was her age and he never soiled his pen or crate. I think they just sleep mostly!
If you decide to do the daycare I would try to do the daycare one day, and then leave her home the following day. Henry was always so pooped out after daycare he would be sleepy even the next day. And around here is is actually cheaper to send your dog to daycare for a full day than it is to have someone come walk them at lunch time...go figure.