none of the above. you are posr=ting from online which would seem to indicate you get a w-2 (not self-employed). employee business expenses are no longer deductible for federal purposes and have never been deductible for Illinois personal income tax purposes.  even if self-employed you have not provided enough information to determine if these expenses are deductible.  explain why you need would need to stay at a motel or use a camper. what type of work are you doing?  as to the camper are the payments lease payments or payments on financing. if the latter what's the cost of the camper.

if you don't have a permanent place of domicile motel expenses would be a nondeductible personal expense and as to the camper only interest and property taxes would be deductible as an itemized deduction subject to whatever limitations are in effect for that tax year.

The question misunderstands the value of a "write off".  You can reduce your taxable income by ordinary and necessary expenses of your job.  But you have to pay the expenses in the first place, and that still comes out of your after-tax income sooner or later.

For example, assume you take an out of town assignment for one month paying $5000.  You can deduct half the cost of meals and your actual cost of lodging.  Assume the meals are $1500 either way.  In situation (a) your lodging is $1200, so your taxable income is $3050, your income and SE tax are about $825 and your take-home is $2,225.  In situation (b) your lodging is $500, so your taxable income is $3750, your income and SE tax are about $1015, and your take-home is $2735.

With the higher lodging expense, you pay lower tax, but you also have less take-home money at the end of the month.  The same would be true of eating restaurant meals 3x per day, or buying groceries.  the higher the expense, the less your tax, but also the less your take-home, since the taxes only offset 30-40% of the costs of the expenses.

And of course, this only applies to self-employed persons (schedule C, independent contractor).  W-2 employees can't deduct any work-related expenses.  However, W-2 employees can be reimbursed by their employer tax-free for work-related expenses if certain rules are followed, if you are being sent on assignment by a W-2 employer, you should discuss the financial arrangements before you agree to take the assignment.