There is probably not a one for one trade or one+ smaller assets that make sense to trade Drai for, and if you trade him for multiple young pieces your pretty much telling McDavid you are rebuilding and they won't be competing until near the time you need to re-sign him. Its essentially a no win situation. Then you get into the fact you locked quite a few guys into deals which are win-now contracts like Nurse, Hyman, and RNH which either have NMC or one's about to kick-in.
Realistically, without a masterstroke of a trade, you aren't getting more value per dollar than Drai on 8.5m which makes it very hard to justify hockey-wise. Politically, it's probably impossible to justify to the one player you want to keep happy. Finally, it's not like there is exactly an easy path to a tear down given the NMC's. It basically puts the Oilers in hockey purgatory, and just hoping they can tweak their team, hopefully find a goalie/coach/gm, and win with it. Because, it will be very hard win a hockey trade trading Drai in the cap world, and I don't think any owner in the league could justify walking away from McDavid/Drai for three more years at their current price points, just hoping to luck out over trying to sell a fanbase on trading two of the absolute best players in the league for a rebuild. Superstars in the cap environment of the NHL are only really meant to be traded in tear down/rebuilds, you don't see Turgeon for Lafontaine type deals anymore.