I have a 2.6 Eddy on my base 29 Decoy with plenty of clearance so a 2.8 may fit with enough clearance although I think only Specialized make such a tyre.
I would strongly recommend to consider a pair of Eddys 2.6. It has markedly improved the bike.
I think the front will be OK which is the main thing for me. Rear might be a challenge for traction but that could actually add to the fun on an ebike.