No you have to unbolt the engine and lift it up about 3-4 inches to get the rest of bolts out of the pan but be careful not to lift it to high it will put too much strain on the tranny mounts just lift it high enough to get the bolts and pan out.
I doubt silicone will seal it good enough to make a difference plus that gets pretty warm down there so it might work for a little bit but not a permanent fix.
you can change the gasket in about 3-4 hours if you have the proper tools a cherry picker being the most important of em.
Is it leaking that bad or just a little spot when you park it overnight
if thats the case i would just leave and keep an eye on your oil level every week or so.
Just remember..."My truck doesnt leak oil, its marking it territory"