I can't give you advice against Wario because I go Charizard in that match-up and haven't played it as Ike for a while, but I can say stuff about Snake after playing Sago for some time. The key is to get in close enough where he can't safely pull out a grenade, but not to telegraph your approach to the point where you get tranquilized and stickied; Snake has a pretty poor approach game except for grenade, claymores (DSmash), C4, and tranquilizer, so getting in hampers his ability to set up. Be especially wary of relying on QD and short-hop FAirs to approach, since tranquilizer (especially B-reversed tranquilizer) will stop you in your tracks. However, tranquilizer can't affect you in the air, so you're safe if they fire too early and you haven't landed yet. Another thing to look out for is Snake's crouch - he can't be grabbed while he's crouching and CC'ing negates Ike's jab, so you'll have to nick him with aerials. In addition, Snake's grenades are also a powerful defensive option both in the air and on the ground; if Snake shields while holding a grenade, it's safer to let it detonate and see how Snake reacts under the shield stun rather than to challenge it and possible get set up into a sticky. You can challenge aerial grenade pulls by hitting Snake's lower body, but I wouldn't recommend NAir'ing his upper body since you can generally wait to see where he throws it or let it blow up on himself. Last but not least, don't let your guard down and keep track of where Snake lays his traps, otherwise
bad things will happen to you.
Because of Snake's poor aerial mobility, he's really susceptible to juggles - outside of trying to DAir and B-reverse grenades or C4s, there's not really much he can do if you shark under him with UAir, NAir, and UTilts (UTilt is especially good for beating out DAir because Ike's arm is intangible). If you read a grenade pull, you can meet him with UAir since it covers a wide horizontal range while avoiding Snake's grenade. Snake is also floaty enough to get QD combos out of FThrow and BThrow, so those options are also available to you if you don't feel like juggling him. Once you get him offstage, edgeguarding him isn't too hard because of Ike's massive range; jumping out and FAiring covers any high recoveries while walk-off FAir and edge grab -> edgehop BAir/DAir covers low recoveries. If Snake tries to blow himself up with C4, you can try throwing out an aerial in the place where you think he'll try to tech.
Overall, IMO this is a fun match-up because of how punishing both characters can be to each other and how tactical you have to be when approaching. However, if you can get through the traps and keep yourself at arm's reach to prevent Snake from setting up anything, then it's pretty one-sided.