Sell as high as you can on Strome. The value won't be any higher than it is at the moment.
I'm not sure if that's true, and I'm also not sure it would be wise to trade him, assuming we are going to trade Kreider.
I have to imagine that there are significant doubts as to whether or not Strome can continue to produce away from Panarin. Yes, he did pretty well at the end of last year without Panarin, but I don't see us getting for him what LA got for Toffoli. Toffoli has been a more consistent player over his career and has better numbers in terms of points and goals per game.
If we were to sign Strome to a 2 year x 5 mil contract, and he continues to produce next year, I can see his value being higher than it is now. It would be a bigger sample size of production and the extra year could add value.
Outside of that, I'm not sure it's in our best interest to trade him. If we trade both Kreider and Strome, that's 2 players lost from our top 6. Strome won't break the bank and he won't require a lot of term to re-sign. We can re-sign him and push that decision off to next year or the year after. Without both Kreider and Strome, we may end up pushing kids into roles for which they aren't ready.
If we aren't going to trade Kreider, then I would be okay with moving Strome, depending on the return. If all teams are offering is a late 2nd round pick, then it's really not worth it IMO.