As so often this depends on your definition of laptop - which is not an exact one either. There where many level of size and weight between a bulky schleppable like a Compaq Portable and a notebook sized computer. And only a few would work well on a lap. I wouldn't consider the T1100 be one of them.
Still, with the T1100 as cornerstone, I think the Morrow Pivot of 1984, and its successor, the Pivot II of 1985, also sold as Zenith Z-171, would qualify. It was an 8088-based PC clone with one or two 5.25" drives and could operate from an optional battery pack.
(Picture taken from Wikipedia)
Another candidate could be the Visual Commuter 1083 of 1983. While it looks more like a laptop, due the conventional style of opening the screen instead of keyboard, it's way bigger than the Morrow Pivot (*2). In fact, it's so wide (and quite low, less than half height), that it makes the 5.25" drives look like 3.5".
(Picture taken from Oldcomputers.net)
And then there is of course what could be called 'Lunchbox' format (*1), best known from the Compaq Portable III of 1987, but actually introduced around 1985 by Taiwanese manufacturers. Being somewhere more portable than the classic luggables and definitely more flexible due the large interior it was quite successful from the mid '80s to mid '90s, producing an endless stream of variations, many including 5.25" drives and batteries, even way into the 1990s.
(Taken from Oldcomputer.info)
They (the lunchboxes, not 5.25"s) cover a niche until today for special to type configuration (like for embedded systems maintenance) or portable high performance machines.
A somewhat stretched candidate would be an Apple IIc like Tofro mentioned in a comment. Unlike assumed, there was an LCD available (from Apple and third party), as well as battery-packs (third party). Still, it lacks the easy portability - at least before some glue (or a bag) is applied :)
(Taken from Obsolete Computer Museum)
*1 - According to Tofro :))
*2 - Sizes as width x height x depth
- Morrow Pivot: 32 x 25 x 14 cm (12,8 x 9,8 x 5,5 inch)
- Commuter 1083: 45 x 9 x 38 cm (18 x 3,5 x 15 inch)
- Compaq Portable III : 41 x 25 x 20 cm (16 x 10 x 8 inch)