I split Abasaglar (which is similar to Lantus), ~50-50% and it generally works ok, though in the last month I had reduced my evening dose by 1U (it was 9 + 9, morning + evening) to prevent running low overnight. Now, not having done much exercise for the past couple of weeks due to weather and work I'm back to 9+9 and wondering about putting it up more! (or perhaps I have a lurgie lurking, always hard to know.)
When I used to take the full 18U in the evening I would run low overnight after exercise, even without exercise I'd be trending downward overnight; with the split there's no issue (so there's obviously a reasonable degree of lumpiness there as others have mentioned.)
I also find that for long days with exercise I can take my full evening dose the day before, significantly reduce the morning dose (e.g. take 3,4 or 5U depending on what I feel like) so I don't have to eat constantly during the day while riding my bike, then take usual evening dose (or sometimes slightly reduced to avoid going low overnight if it's been a mammoth day). It works, it could almost certainly be made to work using a different basal insulin too, but I just wanted to add that it is possible (for me at least, we're all different!)
I also have FotF, so have to take bolus irrespective and in addition to what I take to cover anything I eat as soon as I get up (would be better to take it 20min before I get up, but I can't really face getting up any earlier than I really need to for school runs!) FotF can be reduced/eliminated by lots of exercise or alcohol the previous day, though I don't think either of these is particularly sustainable as a solution! 🙂