It would be ridiculous if he had a longer contract still running, but he could leave on a free in June 2020. I think this is a weird situation for all parties. As much as Chelsea don't want to lose him, maybe they should be glad he seems to really want to go this summer, and not wait another year. Imagine the money Hazard would get thrown at him by clubs who could sign him for free. Most likely that 70m offer is an initial low bid to get talks starting, but I'm not sure how high his market value should be. 100m+ would seem like a lot, but on the other hand, it's starting to look like any decent player costs 50m nowadays.