Looking to replace 700c tires with mountain bike like tires
Obviously, your tire needs to be 700c. Larger sized 700c tires (e.g. for mountain biking) are sold as 29" tires. In theory, any 700c/29" tire will fit on the rim. However, you want to match the tire size to the rim width to the rim you have (lest you have bad handling/rim failure by fitting a too big tire). As for the maximum size you can put in, it is also determined by the frame. You need a few mm of clearance (at least 3 mm) between the tire and the frame. You can measure your current tires clearance and use that as a rough guideline for the tire size you can go up to (even though two tires are marked as the same size, there will be some variation to the sizes, which can affect clearance).

It looks like the bike ships with 700x37 tires, which are quite large to begin with. If you want more comfort, you can try running a lower pressure. If you want knobs, I'd look at a cyclocross tire. There are tons of variations, but if you're on a clean road, you don't want too much knob since that just adds resistance, noise and reduces handling. For snow on the road, some knobs can be helpful.