I will join longneck, you need to give to give this one to a pro.
If you do not understand about back-feeding a circuit, already, it is too easy to kill someone. I say this without exaggeration.
The biggest problem with running a generator with a transfer switch is that you have to wire it into your main panel.
For basic protection of life, (as well as the law,) it must NOT be possible to have your generator and the power to your house on the same wire, at the same time.
This is not a case of, just for a few seconds, or I would not do that, or I will triple check a written list.
It must not be possible under mechanically, electrically, on with quantum physics.
The reason is that if you put power on the 'dead' wires to your house, it is possible to kill someone a mile away, or more.
Emergency workers expect down lines to be dead. Yes, they do check first, but that does not mean that the situation can not change while they are working on them.
Transformers work backwards, low voltage at your generator (240) quickly becomes high voltage (thousands).
And sometimes people, and pets, or cars, just do not even see a fallen power line.
This is a case of some money to a pro vs life.
Typically a "drop-in" range will rest on the adjoining counter top surfaces.
That the actual cabinet is narrower, gives you the wiggle room you need to drop in the unit to install it.
If you want to change to a cooktop installation, that is something that is only supported by the counter top, then you'll need to build a cabinet, and provide a counter top with cutout to fill that space.
In any case, as others have suggested, check the exact measurements of any product that you select. In this age of the internet, most manufacturers have their Installation Guides online, you can pull a copy in spite of the retail staff.
Best Answer
Generally yes can use part of your range. Each burner is different, I've seen 8" burners use up to 2500 watts, smaller can be 1200 to 1500.
I have even baked a pie. However I had to trick the oven by preheating on the broil setting since preheating on the bake setting uses both top and bottom elements and my biggest generator is a 5500.