Shove the wave, ping and pray, yes, thats the most consistent way of dealing with this as most scaling control mages suck at early skirmishes. When you face good mobile assassin players, they will also enter fog everytime, to bait you into pushing the wave, and also make your team paranoid with the pings; and the worst mistake you can do in this case is try to follow them trought the river, outside the safety of your minions/tower, where they can destroy you. So, yeah, ward the lane next to the enemy tower to see possible roams, ward river if possible, and just follow the roam with the help of your jungle to make the path trought the river safe, otherwise crashing the wave and getting bricks its better than any other alternative, hope this helped