You’ll probably be able to read your Kindle as your plane climbs into the sky on the way to Grandma’s house for the holidays, but if you bought a discount plane fare and refuse to pay extra for early boarding, you might have trouble finding space for your roller bag.

Like bags in an overhead bin, flying conditions tend to shift, and there are some new wrinkles as this year’s holiday travel season approaches.

One good piece of news is Federal Aviation Administration’s relaxing of rules on the use of portable electronic devices on airplanes. The way the airlines are trumpeting the change, you’d think travelers were about to get food or something. But the change is simple: Previously, you were able to use electronic readers, tablets and phones in airplane mode (using onboard WiFi if available), only above 10,000 feet.

Now, you can do exactly the same thing below 10,000 feet. You gain 10 to 20 minutes of extra time for reading, game-playing and emailing. You still can’t make phone calls or send texts.

JetBlue and Delta were the first airlines to relax their electronics rules, with American and United close behind. FAA spokesman Lynn Lunsford says he expect every major airline to offer the relaxed device use by the end of the year.

The second positive change is that more travelers than ever are enrolled in TSA’s Pre-check program, which lets you keep your shoes and belt on, keep your laptop in your bag and go through security in a special line. TSA says nearly 18 million travelers “have experienced” Pre-check, although not all of those are enrolled. (Recently, TSA has begun occasionally pulling unenrolled people to send through the Pre-check line; that’s how you can “experience” it without being enrolled.)

Right now, Pre-check is primarily for people considered elite passengers by certain large airlines. It’s not a matter of how often you fly; it’s a matter of how much you spend. You can also get into the Pre-check line by being a member of Global Entry, which also gets you into a speedy passport-check line when you return from traveling abroad. Global Entry application costs $100 and involves passing a security clearance and personal interview.

Now for the bad news: Airlines are providing more and more chances for you to pay extra to get on the plane early. Getting on the plane early, as you know, equates to getting bin space for your carry-on. When you book your ticket, you get a chance to pay extra for priority boarding on most airlines. Some even often a second chance at the gate.

It’s gotten to the point that on many flights, more than half the passengers are in some sort of priority-boarding group. Some airlines — United, for example — flat-out tell you on certain flights that if you’re in the last boarding group, you have no hope of getting any bin space.

So, what are you to do if you don’t want to pay extra? First, if you have a credit card affiliated with an airline, sometimes paying for your ticket with that card will get you priority boarding. Second: If you’re carrying on a roller bag, also take a carry-on that can fit under the seat for your wallet, keys, valuables, prescriptions and electronics. Your wheelie bag, then, should contain only clothing. If flight attendants have to gate-check the bag, your important stuff stays with you.