If this is your north MI location, you'll want at least R10 between the tubing and the slab or you'll be spending quite a bit on heating up the sub-slab dirt. That would add at least 3" on the slab section.
If you have crawlspace or basement under the other part with a joisted floor, you can still put radiant under that part, and use low-temp panel radiators or radiant ceiling on the slab area.
In general the economics of retrofit radiant is kinda out-there, and there are trade-offs to be made.
By contrast, replacing fin-tube baseboard with panel radiators is cheap, with a large uptick in creature comfort with more stable room temps and quicker response times than most radiant floor types.
With the exception of just replacing functional fin tube with panel radiators of equivalent output, going with radiant for even part of it is a real hydronic design problem. Like any heating system design, the only way to zoom in on the "right" solution starts with a room-by-room and whole-house heat load calculation. If the fin-tube seems to have reasonable room to room temperature balance we can cheat a bit, and measure the fin tube length in each room, and use fuel-use against heating degree-days for a mid-winter bill to determine the whole house load, which will tell you how much of what type of radiant it would take to meet the 99% outside design temp load in your zip code.
Without all of the necessary information it's kind of like asking, "Is it possible to get to town on my bike in under two hours?". It really depends on several things, like where you are, and where the town is, and whether you've been pumping up & doping in prep for the Tour de France.
Bottom line, it's always possible to add heat to the floor, but how much of the total design heat load it covers and how much it costs will vary by orders of magnitude.